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A Taxonomy of Safeties

In addition to the other two posts so far today, I am sharing another one of Hognose’s posts from Weaponsman.com.  This is a repost in our ongoing commitment to honoring  our dead friend Kevin and his work.

A Taxonomy of Safeties

by   Kevin O’Bien “Hognose”

There are several kinds of safeties that are used on service weapons to ensure that only the proper and deserving people are shot. They generally interface in some way with the firing mechanism of the firearm. They may act on the trigger, the hammer or striker, or the sear, or (in some fiendishly clever arrangements) more than one of the above. It is generally thought better to positively lock the striker or firing pin than merely to lock the sear or trigger. If the mechanism fails due to parts breakage, it is easier to design a fail-safe mechanism if the striker or firing pin is immobilized.

Safeties Classified by Operator Volition

Safeties can be classified based on the degree of volition required to use them. An applied safety must be consciously put on, in most cases. An automatic safety is unconsciously applied as the pistol is taken up. Examples of automatic safeties include:

  1. the Glock Safe Action trigger and its many copies and derivatives;
  2. the grip safeties characteristic of many Browning designs, such as the M1911 .45 and the FN M1910 pocket pistol;
  3. similar grip safeties on open-bolt submachine guns such as the Madsen and the Uzi. (An open-bolt SMG poses peculiar safety problems);
  4. transfer-bars and other means to ensure a weapon can’t fire unless the trigger is pulled;
  5. mechanisms that hold a firing pin back until a weapon with a locking breech is fully in battery (the disconnector often does double-duty as this part);
  6. Firing-pin immobilizers as in the Colt Series 80 and newer M1911s (an earlier firing pin safety, the Swartz Safety, was used in commercial Colt 1911s from circa 1937 to 1940, and is used by Kimber today);
  7. A heavy, smooth trigger pull such as that on a traditional Double Action revolver or a DA/SA autopistol can prevent unintentional discharges. However, some heavy triggers (like the Glock NY2) have a bad enough effect on accuracy as to threaten bystanders with unintentional shooting.
  8. Magazine safeties, an obsolete European concept;
  9. Half-cock notches (in British/European English usage, these may be called half-cock “bents.”)

Contrasting with these automatic safeties, that do their work without conscious application by the operator, there are Applied or volitional safeties. Applied Safeties are usually classified by what part of the firing mechanism they work on, and so examples of Applied safeties break down into:

  1. Safeties that lock the trigger. The simplest of these are the crude trigger-blocking safeties on an SKS or Tokarev SVT. More complex trigger-locking safeties are found in the AR series of rifles and the FN-FAL;
  2. Safeties that lock the firing mechanism (which may be further divided into those that lock the firing pin, like the Walther P.38 or Beretta M92, and those that lock the hammer, like the US M1 Rifle, or
  3. The bolt holding notch in many 2nd-generation submachine guns. (These are reminiscent in a way of the safety of the Mosin-Nagant rifle, which requires the cocking piece to be rotated and caught in a notch). The case can be made that this is a firing mechanism lock, because the bolt with its fixed firing pin is the firing mechanism.
  4. Safeties that lock the sear. Examples include the .45 M1911, its younger brother the BHP, many other auto pistols, and most general purpose machine guns. Some require the weapon to be cocked to lock the sear, others allow locking the bolt forward (the RPD LMG and the Sterling SMG are examples of this).
  5. Safeties that disconnect the trigger from the sear. This is found in the Bren gun and many other Czech designs, historically. The ZB 26 and its derivatives were quite cunning: in one position, the selector brings the trip lever to engage the semi notch, which is in the upper side of a window in the sear. In the other position, it engages the auto notch in the lower side. In the intermediate, “safe,” position, the  trip lever clears both notches and the weapon does not fire.

Note that automatic safeties, too, can be broken down as working on the trigger, the firing mechanism, and the sear, also. So safeties can also be Classified by Operation.

Safeties Classified by Operation

It is possible to classify safeties in the first place by their means of action:

  1. Trigger safeties
  2. Firing-mechanism (striker, hammer, firing pin) safeties
  3. Sear safeties
  4. Disconnecting safeties.

This is true, obviously, for both automatic and volitional safeties, and classifying them this way puts their mode of action forward as more important than their mode of engagement, which (applied/volitional or automatic) becomes a secondary trait.

One More Trait: Must the Firearm be Cocked?

It is only possible to engage many safeties when the weapon is cocked or ready to fire (presuming a chambered round). Familiar examples include the AR series rifles and the 1911 pistol and other Browning hammer designs. Other safeties engage regardless of the energy state of the striker or hammer, for example the AK, the Remington Model 8 (a Browning-designed trigger mechanism that was deeply influential on 20th and 21st Century firearms designers, including Garand, Kalashnikov and Stoner), and the RPD light machine gun.

Combination Safeties

While a weapon may have multiple safeties that do different things (or multiple modes that engage the same safety, as in the safety lever and grip safety of early Lugers), it’s possible for a single cunningly-designed safety to disable multiple points of the firing chain at once. For instance, the Lee-Enfield safety is a model of versatility: it locks the striker, locks the bolt closed (preventing the chambering of a round), and disconnects the striker from the sear. The M1911 or Browning High-Power safety locks the slide closed as well as locks

It’s also possible for a volitional safety to be combined with other functions. The most common example of this is the combined safety/selector switch of most modern assault rifles, like the M16 or AK-47.

To Sum Up

There are a great but finite number of ways to design safety features on modern firearms. Careful study of prior art allows today’s designer truly to stand on the shoulders of the giants in the field. John Browning left no memoir or technical book, nor did John Garand, John D. Pedersen, Gene Stoner; and the many memoirs of Mikhail Kalashnikov are disappointing to the technical reader. But each of these geniuses spoke to us in the art of his designs, and they are still available for us to study and to try to read what their art is trying to tell us.

We have not, in this limited post, attempted to discuss “best practices” or the pros and cons of any individual safety design. Very often, the designer will be limited by the customer’s instructions or specifications. (For example, the grip safety of the 1911, which 1970s and 80s custom smiths often pinned in engagement as a potential point of combat failure, was requested of John M. Browning by the US Cavalry. The other military branches didn’t feel such a need, but the horse soldiers did, and Browning first added it on his .38 caliber 1902 Military pursuant to a similar request). Thus, even as a designer, your safety design decisions may not be your own.

Notes and Sources

  • This post has been modified since it was first posted, to expand it.
  • This post will be added to The Best of WeaponsMan Gun Tech.

This post owes a great deal to the following work:

Allsop, DF, and Toomey, MA. Small Arms: General Design. London: Brassey’s, 1999.

Chapter 13 is an extensive review of trigger mechanisms, including safeties, and while their classification of safeties is different from ours, their explanations are clear and concise.

Thanks to the commenters who not only recommend this long out-of-print book, but also sent us a link to a bookstore that had it (it’s a copy withdrawn from a military library, as it turns out). This out-of-print work is less technical and deep, but considerably more modern, than Balleisen; its examples are primarily British.

Kevin was a former Special Forces weapons man (MOS 18B, before the 18 series, 11B with Skill Qualification Indicator of S), and you can expect any guest columnists to be similarly qualified. He passed away early last year.

What’s so special about John Moses Browning?

This post is a re post from weaponsman.com. We share it here today to honor and preserve our friend Hognose, who died last spring 

What’s so special about John Moses Browning? by Kevin O’Brien

 

Himself.

Himself.

If you take that question the wrong way, you’re thinking who is this bozo to diss Saint JMB? But we’re not putting the emphasis on the JMB side of the sentence, but the What’s so special? end. As in: we really want to know. Why is this guy head and shoulders above the other great designers of weapons history? What made him tick? What made him that way?

Browning was not a degreed engineer, but he is, to date, the greatest firearms designer who has ever lived.  Consider this: had Browning done nothing but the 1911, he’d have a place in the top rank of gun designers, ever. But that’s not all he did, by any means. If he had done nothing but the M1917 and M1919 machine guns, he’d have a place in the top ranks of designers. If he’d done nothing but the M2HB, a gun which will still be in widespread infantry service a century after its introduction, and its .50 siblings, he’d be hailed as a genius. One runs out of superlatives describing Browning’s career, with at least 80 firearms designed, almost 150 patents granted, and literally three-quarters of US sporting arms production in the year 1900 being Browning designs — before his successes with automatic guns.

He did all that and he was just getting warmed up. He didn’t live to see World War II, but if he had, he’d have seen Browning designs serving every power on both sides of the war. If an American went to war in a rifle platoon, a Sherman tank, a P-39 or P-51 or B-17, he and his unit were gunned-up by Browning. If he made it home to go hunting the season after V-J day, there were long odds that he carried a Browning-designed rifle of shotgun, even if the name on it was Remington or Winchester. Browning’s versatility was legendary: he designed .25 caliber (6.35mm) pocket pistols and 37mm aircraft and AA cannon, and literally everything in between. He frequently designed the gun and the cartridge it fired.

A lot of geniuses have designed a lot of really great guns since some enterprising Chinese fellow whose name is lost to history discovered that gunpowder and a tube closed at one end sure beats the human hand when it comes to throwing things at one’s enemies.  But nobody comes close to Browning’s level of achievement; nobody matches him in versatility.

So why him? As we put it, what’s so special? 

We think Browning’s incredible primacy resulted from several things, apart from his own innate talent and work ethic (both of which were prodigious). Those things are:

  1. He was born to the trade
  2. He was prolific: his output was prodigious
  3. He was a master of the toolroom
  4. He lived at just the right time
  5. He could inspire and lead others

Born to the Trade

John M’s father, Jonathan Browning, was, himself, a gunsmith, designer and inventor. He made his first rifle at age 13, and despite being an apprentice blacksmith, became a specialist in guns by the time he was an adult. From 1824 he had his own gunshop and smithy in Brushy Fork, Tennessee, and later would move to Illinois (Where he befriended a country lawyer named Lincoln). He joined the Mormons in Illinois and fled with them to Utah, making guns at each way station of the Mormon flight.

Jonathan Browning Revolving Repeater

Jonathan Browning Cylinder Repeater. Image from a great article on Jonathan Browning by William C. Montgomery.

Very few of Jonathan’s rifles are known to have survived, but he made two percussion repeating rifles that were, then (1820s-1842), on the cutting edge of technology. The Slide Bar Repeating Rifle  was Jonathan’s term for what is more widely called a Harmonica Gun. The gun has a slot into which a steel Slide Bar is fitted. The slide bar had, normally, five chambers; after firing a shot, the user cocked the hammer and moved the Slide Bar to the side to move the empty chamber out from under the hammer, and a loaded chamber into place. When all five chambers had been discharged, the Slide Bar was removed, and each chamber loaded from the muzzle and reprimed with a percussion cap. Jonathan Browning’s gun differed from most in that it had an underhammer, and that an action lever cammed the Slide Bar hard against the barrel to make a gas seal. He also made a larger Slide Bar available — one with 25 chambers, arguably the first high-capacity magazine.

The second Browning innovation was the Cylinder Repeating rifle. This was a revolver rifle, with the cylinder rotated by hand between shots. Like the Slide Bar gun, the cylinder was cammed against the barrel to achieve a gas seal — the parts were designed to mate in the manner of nested cones.

Young John M. Browning. From the Browning Collectors web page.

Young John M. Browning. From the Browning Collectors web page.

The designer of those mid-19th-Century attempts to harness firepower sired many children; like other early Mormons, he was a polygamist, and his three wives would bear him 22 children. From age six one of them apprenticed himself, as it were, to his father. Within a year he’d built his own first rifle. This son was, of course, John Moses Browning.

(Aside: the last gun made by Jonathan Browning was an example of his son’s 1878 single-shot high-powered rifle design, which would be produced in quantity by Winchester starting in 1883).

Malcolm Gladwell has popularized the idea that it takes 10,000 hours of hard work to become an expert — that’s roughly five years of fulltime labor. JMB had exceeded this point before puberty.

If you aspire to breaking Browning’s records as a gun designer, you need to acknowledge that, unless you started from childhood, you’re starting out behind already.

Prolific Output

Browning worked on pistols, rifles, and machine guns. He worked on single-shot, lever, slide, and semi-automatic actions, and his semi-autos included gas-operated, recoil-operated, direct-blowback, and several types of locking mechanism. Exactly how many designs he did may not have been calculated anywhere: it’s known he designed 44 rifles and 13 shotguns for Winchester alone, a large number of which were not produced, and some of which may not have been made even as prototypes or models.

His military weapons included light and heavy infantry machine guns, aerial machineguns for fixed and flexible installations, and several iterations of the 37mm aircraft and anti-aircraft cannon, the last of which, the M9, would fire a 1-lb-plus armor-piercing shell at 3000 feet per second; an airplane was designed around it (the P39 Airacobra, marginal in US service but well-used, and well-loved, by the Soviets who received many via lend-lease). All the machine guns used by the US from squad on up in WWII and Korea were Browning designs. But these were only his most successful designs; there were others. At his peak, he may have been producing new designs at a rate of one a week. 

If you want to to be the next John Browning, you need to start designing now, and keep improving your designs and designing new ones until the day you die. (Browning died in his office in Belgium).

Master of the Toolroom

The Browning workshop, back in the day.

The Browning workshop, back in the day.

From an early age, John learned to cut, form and shape steel. This is something common to most of the gunsmiths and designers of the early and mid-20th Century — if you remember our recent feature on John Garand, the photo showed him not a a drawing board by at a milling machine.

Browning could not only design and test his own prototypes — he could also design and improve the machinery on which they’d be produced, a necessary task for the designer in his day. Nowadays, such production development is the milieu of specialized production engineers, who have more classroom training, and probably less shop-floor savvy, than Browning brought to the task.

A reproduction of Browning's workshop in the Browning Museum in Ogden, UT.

A reproduction of Browning’s workshop in the Browning Museum in Ogden, UT. (From this guy’s tour post).

In Browning’s day, processes were a little closer to hand-tooled prototype work, but it still required different kinds of savvy and modes of thinking .

If you want to be Browning, you have to master production processes, for prototypes and in series manufacturing, from the hands-on as well as the drawing-board angle. There may never again be a designer like that.

Living and Timing

John M. Browning in 1921 with Mr Burton of Winchester and the category-creating Browning Automatic Rifle.

John M. Browning in 1921 with Mr Burton of Winchester and the category-creating Browning Automatic Rifle.

John M Browning lived in just the right time: he was there at the early days of cartridge arms, when even basic principles hadn’t yet been settled and the possibilities of design were wide-open and unconstrained by prior art and customer expectation. No army worldwide, and no hunter or policeman, really had a satisfactory semi-auto or automatic weapon yet (except for the excellent Maxim)

It’s much easier to push your design into an unfulfilled requirement than it is to displace something a customer is already more or less comfortable with.

If you’re going to retire some of John M. Browning’s records, you’re going to need the right conditions and a few lucky breaks — just like he had.

Inspiration and Leadership

To read the comments of other Browning associates of the period is to see the wake of a man who was remarkable for far more than his raw genius. Browning was admired and respected, to be sure, but he was also liked. At FN in Belgium, the gunsmiths called him le maître, “the master,” and took pleasure in learning from him.

M Saive at the drawing board. Image: FN Herstal.

M Saive at the drawing board. Image: FN Herstal.

His Belgian protégé, M. Dieudonne Saive, went on to be a designer of some note himself. While he did not achieve Browning’s range of designs, he, too, is in the top rank for his work finalizing the High-Power pistol (also known as the GP or HP-35) that Browning began, and for his own SAFN-49 and FAL rifle designs, and MAG machine-gun, all of which owed something to Browning’s work as well as Saive’s own.

If you want to be the next John Moses Browning, you have to know when to step back, and how to share the burden — and the credit.

About Hognose

Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF).

The SAWs that never WAS: Part 1 & 2

Since the passing of our friend Kevin AKA “Hognose”  owner of weaponsman.com we have be  reposting   his work here in tribute and to make sure it survives. This is another technical article from Kevin in part of a series.

The M249 Squad Automatic Weapon is widely distributed in the US Army and Marine Corps (even after the Marines replaced many SAWs with M27 Infantry Automatic Rifles). But how did we get to that point, and what other weapons were considered along the way? This series will look at each of the four contenders in turn. The principal objective of this article is to set the stage, and introduce an unfamiliar cousin of a familiar old friend: the XM106 Automatic Rifle, an M16A1 redesigned by Army engineers for the tactical role once filled by the Browning Automatic Rifle in the American rifle squad.

It’s a bit amazing that a SAW program got any traction at all. In 1979, the Army was concerned about the vintage of its small arms and other systems. While we’re most concerned about small arms here, the Army’s RDT&E guys had to develop it all, and they had their hands full trying to field or develop, at that time:

  1. The XM1 Tank (with 105mm gun; not yet named Abrams).
  2. The 120mm smoothbore follow-on for the M1. This was principally setting up American manufacture of an already-successful German gun.
  3. The Infantry Fighting Vehicle and its cav variant (not yet named Bradley).
  4. The Copperhead laser-guided precision artillery shell.
  5. The YAH-64 helicopter (“Y” means prototype; the Army was testing 5 prototypes, but they hadn’t selected the night vision and fire control systems yet; everyone remembered the AH-56 Cheyenne, which had gotten to this stage and beyond before its ignominious cancellation).
  6. The still unnamed MLRS rocket system was in early phases of tests, and precision guided rockets for it were barely on the engineers’ whiteboards.
  7. Improved missiles:  I-HAWK, TOW, and Pershing II.
  8. New missiles: HELLFIRE and Patriot.
  9. US production of the superior British 81mm mortar.
  10. Firefinder radar.

Those are the ones that turned into successful fieldings, but every one was opposed by vocal lobbies, which argued that the weapons cost too much, and would never work. (Some of these opponents were concerned patriots, like John Boyd’s famous reform mafia; others might not have been, like the CDI, a group that toed Ivan’s line so thoroughly that it was rumored to be financed by the USSR, and that did indeed fade from prominence after the USSR went belly up, although no one ever found any proof of anything as far as we know).

To the delight of the opponents, some development projects would turn out to be turkeys, like the DIVAD gun (later named Sergeant York; its fate was sealed when a high-stakes live demo saw it lock on to a latrine fan instead of a hovering, easy-pickin’s drone helicopter). Some would blow their budgets and get put out of their misery by the Carter administration or the Congress. Nobody remembers the US Roland AA missile, or the Stand Off Target Acquisition System, a helicopter with a Rube Goldberg targeting radar that needed a Heath Robinson raising and lowering mechanism.

But all in all, for all that the suits would like to zero out Army R&D, and for all that some projects would be dead ends, the need for these systems was so great, and/or the contractors had promised to manufacture them in so many Congressional districts, that the Army had an RDT&E budget request for $2.927 Billion for FY 80 (which began 1 Oct 79).

The principal small arms program was the SAW (the long-running Air Force/Joint pistol trials, the M231 Firing Port weapon, and a 30mm repeater grenade launcher which never saw type-classification, were some of the others). The Squad Automatic Weapon program was well along; the service needed to complete a developmental and operational test of four prototypes and evaluate the test data. Considering that it would produce a weapon still in the field today, this program’s budget request was almost invisible: $500,000. It was a little less than 2%, not of the RDT&E budget, but of 1% of the RDT&E budget (0.01708% if you do the math; rounds up to 171 10/1000ths of a percent).

The Army had just given up on the idea of a return to a .30 caliber small arm. A study called IRUS-75 evaluated the .30 concept as part of a question of the overall organization and equipment of the future rifle squad; a follow-on study, the Army Small Arms Requirements Study (ASARS), made it clear that the caliber mattered less than having two auto weapons per squad to provide a base of fire, as the BAR had done in days of yore.

The four NATO ammo contenders. Soon after the SAW tests described in this series, NATO chose the SS109.

The four NATO ammo contenders. Soon after the SAW tests described in this series, NATO chose the SS109.

The Army conduced an extensive computer study that determined the optimum caliber for a SAW was 6mm. This caused the first casualties inflicted by the SAW as logisticians’ heads exploded: they had no desire to stock a third caliber alongside 5.56 and 7.62. Accordingly, the SAW was specified to use 5.56mm ammunition: not the standard M193 ball round, but whatever round came out of new NATO testing, whether it was the FN SS109, the US XM777, or something completely different. The test guns were, as we understand it, set up for XM777. (XM777, like SS109, sought to get more penetration out of the 5.56x45mm cartridge by using a steel penetrator. It was, however, backwards-compatible with the 1:12 rifling of earlier 5.56 rifles. SS109 proved superior in NATO tests to SS109 and experimental British and German small-caliber rounds, and was adopted; the US version is M855).

The Army did not have an entirely free hand in weapons development, since the Joint Services Small Arms Program had been established in December, 1978, as “the senior joint services body for small arms development,” but the Army did retain control of the SAW program. By early 1979, four prototypes were under test by the Material Testing Directorate of the Army’s Aberdeen Proving Ground. One of the four was going to be the SAW and replace two of the rifle squad’s M16A1 rifles. (Doctrine at the time designated one rifleman in each fire time the “automatic rifleman”. He got a bipod and more ammo. The rest of the riflemen were supposed to fire on semi-auto against point targets only).

The four candidates were three belt-fed 5.56mm light machine guns: Ford Aerospace’s XM248; FN’s XM249; H&K’s XM262; and one magazine-fed weapon, the XM106.

Screen Shot 2013-10-27 at 11.09.28 PM

The XM106 had the home-field advantage: it was developed by the Army’s own Ballistics Research Laboratory. But it was, by far, the least advanced rifle. It was essentially an M16A1 with a modified fire-control system and a bipod. It fired full-auto only, from an open bolt, and had a heavy buffer system to bring the rate of fire down to 750 RPM. The bipod was an M2 bipod, as used on the M14, but it mounted above the rifle’s barrel. All XM106s appear to have been hand-built, toolroom guns, and there are a few variations among them. The XM106 had a clever, but complex, interchangeable barrel, a desirable feature in a weapon that may be called on to deliver lots of automatic fire. In most XM106s, the front sight base was moved closer to the muzzle end of the barrel (which army records record as 482mm [21.5 in.] including the flash suppressor, the second longest of the contenders), reputedly to extend the gun’s sight radius.

XM106 removable barrel version.

XM106 removable barrel version.

The barrel-changing mechanism removed the front sight and gas tube from the gun, leaving the bipod attached to the receiver. The handguards, as you can see in the picture, split. This system had two drawbacks — one, shared with the M60 and numerous other GPMGs is that rear sight adjustments could only be zeroed for one barrel — when you changed barrels, you changed point of impact, and it might have done something ugly to the accuracy of your weapon. The second drawback is clearly visible in the picture: that gas tube hanging off the spare barrel, just asking some GI to bend, break, or plug it with something.

The XM106 was not only magazine-based, it had its own special magazine — sort of. A spring clip held three 30-round magazines together. When one was exhausted, the auto-rifleman pressed the magazine release and shifted the mag over and reinstalled it. It was another Rube Goldberg / Heath Robinson contrivance, but in the late 1970s there were no reliable high-cap magazines.

We’re not aware of any surviving XM106s. The open-bolt mechanism and the plate renaming the fire selector positions lived on, however, on the M231 Firing Port Weapon. Colt was to reevaluate the M16-based MG and develop a version in conjunction with Diemaco for Canadian Army tests; that would also fire from the open bolt, but it had a superior barrel change system and bipod to those of the XM106.

If the XM106 was the least technically ambitious of the SAW contenders, Ford’s XM248, which instantiated some concepts developed at BRL and elsewhere in the Army ordnance world, was at the opposite end of the spectrum — a technical stretch. But that’s for the next installment.

Other than its influence on Colt’s future private developments, the XM106 was an evolutionary dead end. With four very different guns to choose from, three had to lose, and with its lack of a belt and awkwardness, the XM106 was never really in contention. It’s interesting to compare it to the M27 automatic rifle the Marines ultimately chose to replace most of its SAWs, a weapon that accepted the inconvenience of magazine loading for the benefit of much lighter weight.

That the XM106 was so quickly set aside tells us that “not invented here” wasn’t holding the Army ordnance experts back in the late 70s and early 80s — the gun was designed by their own compadres at the Ballistics Research Laboratory, but it wasn’t the best. Any disappointment that BRL might have had was limited, however. Their firing-port weapon design, a more extensively modified M16A1, was adopted as standard equipment for the new Infantry and Cavalry Fighting Vehicles, and it, too remains in service today — so there’s a little bit of XM106 still out there.

In Monday’s installment, we gave you the overview of the SAW program as of 1979, and we looked in depth at the least radical design, the magazine-fed M16 variant, XM-106 automatic rifle, a product of the Army’s own Ballistic Research Laboratory. Today’s installment will fill you in with a little more on the competition and its history, and will go into a little depth — unfortunately, a little depth is all we have — about the XM-248 and especially its forerunner, the XM-235.

To recap, as of the beginning of 1979 four candidates were being compared for a concept of a Squad Automatic Weapon that was then (barely) filled in the infantry fire team by giving one guy a stamped-steel bipod and permission to set his selector to Crowd Control. Along with the XM106, which was an M16A1 with some concessions to firing high rates and volumes of automatic fire, the contenders at this point were three belt-fed 5.56mm light machine guns: Ford Aerospace’s XM248, FN’s XM249 and H&K’s XM262.

XM248

The XM-248 is a good-looking gun with a straight inline mechanism and a very clever belt feed that had the potential to be more positive, but less upsetting to accuracy, than the typical feed tray that’s been standard on GPMGs ever since the MG34 instantiated the category way back during the Great Depression.

To understand the XM248, we have to roll back a bit, to the very dawn of the SAW program in 1975 (the term “SAW” dates to 1970, and the idea of an intermediate gun between the rifle and the 23+lb M60 GPMG dates to 1966). The Army’s Training and Doctrine Command had noted that a war in Europe was possible, and Europe was vastly more built-up than in the last war. Even then, much of the fighting was in cities — dismounted infantry terrain. A squad automatic weapon that could deliver fire in high volumes would benefit such a squad, in what the Army now calls Military Operations in Urban Terrain (MOUT) and then called Military Operations in Built-up Areas (MOBA). So in 1975, the Army began designing in its own labs, and calling for, from industry, a new weapon, at the same time it began to evaluate M16 improvements that would lead (through a winding path blazed mostly by the USMC) to the M16A2. Both improvements were aimed at MOBA as well as just generally increasing the lethality of the squad, and drew upon TRADOC studies that said fire volume was more important than fire precision.

6x45mm_compared

The 6.0x45mm cartridge, centered between the 5.56 and 7.62 NATO.

The new SAW — the squad’s volume-fire weapon — would use either an optimum cartridge or the standard rifle cartridge. (Each approach had its adherents). The first round of paper SAW candidates were chambered for disparate cartridges, including a new experimental 6mm and the standard 5.56mm. The 6mm fired a 105-grain projectile at 2450 fps (6.8g/.747m/s) compared to the M193 round’s 55gr/3250fps (3.5g/990m/s), giving the new MG a range beyond 800m. One of the main drivers of the 6mm caliber wasn’t anything to do with ball ammunition — it was that given the tracer technology of the time, no known compound could trace to and beyond 800m in daytime, and be contained in the volume of a 5.56mm projo. Army ordnance guys really liked the 6mm; loggies, and the senior generals who would have to square a new caliber with our NATO allies, were more reserved, for entirely non-technical reasons.

Because it was no longer in production or actively being promoted, the Stoner XM207E1 was out of the picture. In any event, the Army’s ordnance officers had a strong prejudice against it: the SEALs loved the gun and used them until there were no parts to be had, but the Army considered it too maintenance-intensive to be reliable in the hands of draftees with GT Scores of 80. Likewise, Colt’s CMG-2; and like other guns rejected before the contest began, they fired the 5.56mm cartridge, which didn’t meet the Army’s desire for an 800m+ weapon.

xm233The three contenders in the 1975-76 round were made for the 6×45 cartridge and given sequential model numbers. XM233 (left) was Maremont’s entry. As you might expect from the maker of the M60, it looked like a baby 60. The XM234, a spindly-looking thing, was prototyped by Philco (about which, more below). And the Army’s own Rodman Laboratories (at Rock Island Arsenal in Illinois) developed a radically new concept which was labeled XM235.

Two more-familiar 5.56mm guns that were being developed in Europe and entirely outside the Army competition at the very same time were not considered at this time: the FN Minimi and the H&K HK23. Ironically, they were rejected specifically because they were 5.56mm weapons. But we haven’t heard the last of the little round and these two commercial guns, either, because in Developmental Test/Operational Test 1, they, and a heavy-barreled variant of the M16, were used as controls and benchmarks for the “real” 6mm guns.

Philco’s 6mm gun was called the XM234, and it looked like this:

xm234

And that picture is almost all we know about it. At the time, we recall reading, and laughing about, the idea that Philco had entered a gun in the Army competition. Philco was the subsidiary of Ford that made the radios and 8-track players (don’t we keep telling you, The Past Is Another Country? Some of us lived there). And so, the idea of it making machine guns was pretty funny. But Detroit automakers are no slouches on mass production, and the Army has often turned to them when it needed quantity and quality. In World War II, the Navy threw a young officer named Henry Ford II out so he could take over from his ailing father and take charge of Ford’s war production, which included guns, gun parts, and complete B-24 Liberators. GM made M3 grease guns, and later would produce M16A1s with considerably less drama than Colt, despite a rather lacking Technical Data Package. So, Philco probably could make a gun; auto manufacturing technology was effective for guns; and mechanical engineering is the same discipline of materials, statics and mechanics for a gun designer that it is for a guy designing a valve train or power-steering mechanism.

By the time the 11th Edition of Small Arms of the World, from which a number of these facts and photos are taken, was published in 1977, the defense branch of Philco had taken on the more dignified name, Ford Aerospace & Communication Corporation.

There’s very little information about the Philco entry available, especially online;  and at the end of the first phase, DT/OT1, in December, 1974, both its gun, the XM234, and Maremont’s weren’t what Army evaluators were interested in. But they really liked the Army’s entry, the XM235:

xm235

The XM235 had been developed by a dedicated team at Rodman, led by Curtis D. Johnson and including at least 7 more dedicated engineers, who all signed on to the patent US # 3,999,461 on the gun (USPTO link) (Google Patents link).

General Arrangement from Patent 399,461 is unmistakably the XM235.

General Arrangement from Patent 399,461 is unmistakably the XM235.

One of the controls also fared well at the tests: the FN Minimi was as reliable as the best of the 6mm guns, and more so than the H&K. It used then-special FN ammo (SS109) which didn’t interchange with the riflemen’s 1:12 M16s. Nobody liked the HB M16 as a SAW.

At this point, the Army dropped the idea of the 6mm round. It not only complicated Army logistics to have a third entire caliber, but it would be hard to sell to NATO, where American allies had already had two Yankee cartridges rammed down their throats. So the SAW was going to be 5.56mm. How were they going to get the 5.56 to perform “beyond 800m” as the spec had said? They weren’t. So the new spec was “up to 800m.”

This set the Army up for the next round of testing, but they needed someone to produce the XM235. The prototype that so impressed everyone at DT/OT1 was handbuilt, and the Rodman guys weren’t manufacturing or production engineers. The answer seemed obvious: let Maremont and Philco, uh, Ford Aerospace, bid on producing the the XM235. Ford won the bid, and engineers being engineers, began improving the design even as they committed to building a couple of dozen prototypes in 5.56 for testing. The 5.56 quasi-production variant of the XM235 was the XM248.

Let’s take a look at the XM235 technically and see why it was so admired at the time. We’ll push back Ford’s many changes that produced the XM248 till tomorrow. (This post is already 1500 words long!)

The Rodman engineers began with a clean slate and the understanding that, other things being equal, automatic weapons firing bursts had always been less accurate than rifles firing single aimed shots. This wasn’t invariably a bad thing, as it allowed for the natural dispersion of a burst to “correct” in a way for a gunner’s aiming error, but it was terribly wasteful of ammunition.

Engineers being engineers, they asked why the automatic guns were less accurate, and they concluded that several things degraded the accuracy of automatic weapons:

  1. Parts of the mechanism were moving whilst bullets were still in the barrel.
  2. Whether operated by recoil or gas, the operating mechanism reflected excess energy back into the weapon, what the developers called “high restitution” from rebounding parts.
  3. Extant light machinegun designs had overly high rates of fire (650 to 1000 rpm).
  4. Peak recoil was high (500-1200 foot/pounds – 2,200-5,300 N).

Those items, taken together, degraded accuracy. So the characteristics sought in the 235 design were:

  1. A long motion of recoiling parts.
  2. A soft cycle without the hammering of buffers on stops often seen in LMGs.
  3. Rate of fire reduced to 500 rpm, little more than half that of an M16A1 with M193 ammo loaded with WC846 powder.
  4. Reduced recoil impulse (to 200 lb-ft) and reduced recoil effects on muzzle movement by careful placement and design of stock and grips, gas system, and so forth.
  5. A change in belt handling to reduce the stop-and-go motion of the belt
  6. Placing parts that induced motion inimical to accuracy (the belt feed, for instance) close to the weapon’s center of gravity, to reduce the moments these parts induced for a given force.

In addition, the engineers wanted to design a weapon with world-class reliability and maintainability. They wanted it to be made up of field replaceable modules, and readily field-stripped in 10 seconds. They wanted to reduce the parts count relative to the M60 (they cut the parts count by 40%).

The receiver was extremely unconventional. What looks like the receiver in pictures is a sheet metal cover with no structural function. The fore-end likewise is a simple stamped cover. The actual receiver comprises two long tubes, a forward end cap that joins the tubes to the barrel, and an aft end cap that contains a sophisticated hydraulic buffer. The bolt carrier rides between the tubes, and connects to upper and lower pistons and springs, which ride inside the receiver tubes (which do double duty as gas tubes). The bolt carrier also contains, of course, the bolt, which has three lugs like an AK bolt, dual extractors and a plunger ejector.

The bolt carrier also drives, in its long travels, a rotating cam tube that turns a feed sprocket that lifts the feed belt with rotary action. There is no reversing or reciprocating motion orthogonal to the direction of fire — unlike the classic MG34/MG42-inspired feed tray cover, or that of the Browning or Maxim for that matter.

XM235 exploded view

A spring-loaded firing pin rode in the bolt, and the fire control and related switchgear were contained in the pistol grip. In order to hang the belt container exactly on the center of gravity, the pistol grip was also hung on the center of gravity front-to-rear but offset to the right. Several effects came packed with this: moments of any operator input on the pistol grip were reduced, because it was at an arm of nearly zero, increasing accuracy; the weapon gave the gunner unprecedented control; and the weapon required right-handed operation. The Army liked the former two, but were keenly aware that about 10% of troops are left-handed. The weapon also required left-handed operation because it was, in effect, a bullpup design. Previous Army skittishness about bullpup safety may have been reduced by measures taken to prevent an out-of-battery firing, and the bolt’s location within the heavy carrier and the solid sheet-metal receiver cover.

Ford Aerospace had the order to produce 18 production-ready XM248s, which were to be the XM235 in 5..56 (instead of the abandoned 6.0×45) with a few improvements. (In the end, they’d make two versions). The improved XM235 was the XM248. Then, post-Vietnam budget cuts savaged the SAW program. The money was there to make the XM248s, but not to test them. The XM235 had been set to compete against the Minimi — if the Minimi could be lightened enough to meet spec — and a couple of USMC-sponsored heavy-barrel M16s (again). That is, in fact, where the 1977 11th Edition of Small Arms of the World left the competition: uncertain, and potentially cancelled entirely. The budget for the competition had been cut so much that the Army had no money for testing the 18 5.56mm XM248s that Ford delivered under their contract, or anything else. IF FN was going to lighten the Minimi, they’d have to do it on their own — contract money wasn’t forthcoming. H&K was fuming on the sidelines, believing their HK23 had been unfairly DQ’d. And Army squads still had, by MTOE, an “automatic rifleman” whose only concession to firepower was a tinny little bipod for his M16A1; alternatively, they could carry a heavy M60 and its heavy ammunition along.

Tune in tomorrow as the XM235 emerges from its Ford chrysalis as the XM248 — and becomes the most advanced light machine gun the US Army ever rejected.

Let’s See Whitworths Shoot!

In our ongoing tribute to our now deceased friend “Hognose” , owner of weaponsman.com , we repost   his best articles.  Kevin O’Brien   US Army Special Forces  Veteran passed away in April of last year.

 

 

Let’s See Whitworths Shoot!

Last month we had a couple posts on the Sharpshooters of the Civil War, and on the Confederates’ unique Whitworth rifle.

Fred Ray, who’s written an excellent book on the Rebel Sharpshooters, sold us a copy of his book (highly recommended, and it’ll be in the next review roundup), and also linked us to a few videos of modern Whitworth shooters. Fred has forgotten more about this stuff than we’ve ever learned, so you can read what he writes with confidence.

Let’s take them in the inverse order from the way Fred posted them: hardest first. Here is a guy trying to hit a target at 1,300 yards with a Whitworth.

That kind of hit was credibly reported by both Rebel and Yankee observers of the Confederate marksmen. (The English Whitworth rifle was only used by the Confederates).

One of the real problems is seeing the target. While many of the wartime Whitworths were equipped with high-tech (for 1860!) Davidson telescopic sights… …this marksman is shooting over irons. One of the real problems at that range is seeing the target. Since more of you are familiar with more modern rifles, consider that the front sight post of an M16A1 rifle subtends just enough arc to match an E-type silhouette at 175 meters.

Another fact that should be evident is the sheer power of the Whitworth. Look at that thing kick! The recoil is visibly greater than that of an ordinary rifle-musket.

Reproduction Whitworths

The class of the repro field is the long-discontinued Parker-Hale, but they are few and far between. After Parker-Hale went the way of all flesh, there was a EurArms repro which used the Parker-Hale barrels with its own lock and stock. Here, Balázs Némeththe proprietor of CapAndBall.eu has gotten his hands on one of them, and not only fires it, but provides a good run down on its unique and remarkable technology.  “The Whitworth,” he notes, “pushed the limits of aimed fire out to 1½ miles.”

Pedersoli is making a new version of the Whitworth. It is available in Europe, but not exported to North America (yet, we hope). Here is his video rundown on the Pedersoli Whitworth. The Pedersoli has hexagonal rifling, but it’s cold hammer-forged. The rifle also has much simpler sights. He did not have a hex bullet mold, so used a .451″ cylindrical round, and still got quite good accuracy at 50 and 100 meters.

The finish on the Pedersoli rifle is, like many of their premium muzzle-loaders, very good.

His enthusiasm for these rifles, so far ahead of their peers that they seemed ahead of their time, is infectious.

Finally, here’s a special treat. It’s our friend from Cap and Ball again, but here he’s firing an original Civil War vintage American target rifle, of the sort that many sharpshooters mustered in with.

If you go to the Fred Ray post that we linked way, way up there, you’ll also see another one about the Civil War buck-and-ball cartridge — the only loading we’re aware of that has its own statue at Gettysburg. But that’s another story!

 

REMEMBERING KEVIN O’BRIEN

We are coming up  on the 1 year  point of the passing of our friend Kevin, also known as “Hognose” the owner and writer of weaponsman.com.

If you have not been to his website which is now preserved as is by his brother as a monument to Kevin, you are missing out on what was honestly the best gun culture blog on the internet.  I will let Kevin’s own words on his website speak for themselves below.

The Best of WeaponsMan Gun Tech

http://weaponsman.com/?page_id=11760

 

Since his passing he has been sorely missed by his family and many friends and readers.    You will have noticed that we often repost a lot of Kevin’s technical articles in an attempt to save them in case something happens to the weaponsman website and to help others discover his writing,

After Kevin died, his brother  had to sell Kevin’s collection and take care of his estate.  When he announced this sad fact of life, he made a post about it on his brother’s website with a list of the many fine firearms Kevin owned.   I was very keen to buy one of Kevin’s guns as something to remember him by and to keep in his honor.

I had just at the time spent a large amount of a few pistols so I was not able to buy  some of the highly desirable pieces like the Johnson rifle.  I was able to buy an old vintage .22 rimfire bolt action rifle.

It is a Springfield single shot from a time before series numbers.

It is in pretty rough shape with several parts missing.  I have been looking online  for the parts needed to restore it to shooting condition.

Much of the parts are missing and it has a pretty tricked out tack to act as a means to keep the bolt knob down.

The rifle was clearly sold as a cheap offering likely for boys. It was made with no buttplate. I know because it has none and has no holes for where the screw to hold one would be.

 

I don’t know the back ground story of how Kevin got the gun or how long he had it. I liked to think he owned it as a boy and imagine him running around the New England woods shooting chipmunks and cans imagining his future  self shooting commie  as the Army Green Beret he became when he grew up.

I hope the gun will get restored by me soon but if not thats ok. I didn’t buy it for that.   I bought it to honor a man I much admired.  And it is one of the most valuable guns in my safe.

If any of you purchased one of Kevin’s  guns from his estate, please let me know and share with the rest of us.

About Hognose

Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF).

How Insurgencies are Broken

This is another re-post from our ongoing tribute to our friend Kevin OBrien , AKA “Hognose”.  Who was the owner and primary of weaponsman.com  who passed away   much too early in the spring of 2017.

 

"Is it safe?"

“Is it safe?” Torture makes for great entertainment, but it’s seldom needed to roll up an insurgent network.

We bumped into an interesting post at a blog called The Lizard Farmer on the subject of COIN intelligence TTPs. He uses the example of an imaginary Texan resistance cell and describes how intelligence practitioners would roll up a would-be “militia” unit. They do this without even a State of Emergency, or tapping the NSA liasons’ at the fusion centers’ direct warrantless access to domestic mass phone and digital surveillance. They just apply the tactics, techniques and procedures that police use now to close criminal cases, which are very close to what intelligence organizations use to unravel, expose, and annihilate insurgent entities.

His specific example begins with a dead body found after a small unit contact. The decedent was sanitized of serial numbered equipment, electronics, ID and identifying marks, and had even defaced his fingerprints. But he still was the thread they pulled to unravel his entire cell. In the end, modern technology (and psychology) have made no man an island — not even a dead man.

He concludes:

These tactics are how insurgencies are broken.  They’re what enabled the system to pin Bin Laden down, catch the Tsarnaevs, and identify drone strike targets in the middle east.

We have to interrupt here to say two things about the Tsarnaevs — they were not caught until after they acted, and there was no great effect of the intelligence effort to hunt them. They were caught because they got in a gunfight with the cops; one (Speedbump) was killed, finished off when his brother ran him over, and one (Flashbang) wounded badly enough that a citizen found him and turned him in, after a botched Gestapo-style house-to-house razzia failed to find him.

Networks are deadly to an insurgency.  Even operating in meatspace can be deadly without the right precautions.  All it takes is for one person to use that phone to call or that debit card to pay and they’ve been nailed in time and space.   Sure you may be using your regular phone (and not your disposable one) to call ma but you’re there and the records show it.  And if your battle buddy does something similar he’s fixed at that time and place as well – so now both of you are associated.  The key is discipline.  When you meet you go completely off the grid.  Completely.  No phone use, no debit card use, nada in and around the geographic area and  timeframe you meet.  Recon and identify how you could expose yourself.  Does a certain route have license plate readers?  Then don’t use it.  Convenience stores?  They all have cameras at the counter and pumps. Nearby ATM machine? Cameras and transaction records.  The golden rule at all times (and I mean all times)  is to ask yourself: How will what I’m doing at this second expose myself and others to identification?

via How They Hunt | The Lizard Farmer.

Emphasis was in the original. Note that already the police work around legal restrictions on using “forbidden” or warrantless unlawful surveillance by the fiction of “parallel construction,” which means, quite literally, presenting false records to the court that were generated to plausibly explain government possession of illegally collected data. Parallel Construction is not a novel GWOT era technique but was used at least as early as the early 1990s in drug cases, both running warrantless wiretaps against organized crime figures and using military intelligence assets against domestic crime groups. In those cases, it was justified in part by a drug case carve-out to Posse Comitatus engineered into being in the 1980s, but once they began doing it they were on the slippery slope of doing it whether they had a drug nexus or not.

The 1990s-vintage botched raids at Waco and Ruby Ridge both used military assets (physical and human) acquired by ATF and FBI agents simply lying and manufacturing a nonexistent “drug nexus” to get what they wanted. They were coached in this by DOJ lawyers (which should be a reminder to you that a lawyer is a man who is trained to lie for a living; that’s why they do so well as politicians). And these seemingly extreme measures of the 1980s and 1990s were taken in the face of routine and small-time crime. You may rest assured, you would-be revolutionaries, you, that the gloves would come off in a shooting insurgency, and you haven’t seen gloves-off yet.

In some ways this is new; in others, it is as old as the Roman suppression of the Jews 2,000 years ago. A good overview of the techniques, minus the modern technology, can be found in the movie, The Battle of Algiers, and that puppy’s over 50 years old.

Even now, in the FBI, which is increasingly redefining itself as the Sword and Shield of The Party1, monitors what it calls “extremists” and is making long lists of who it would like to round up, when The Party lets slip its leash. Erdogan isn’t the only one who had an “enemies list” cued up for neutralization.

So, if you are, say, an antiauthoritarian personality, if the will to resist is strong in you, what can you do without winding up on a slab like “Bob” in Lizard’s post, or in a death-row holding cell like his brother, or having his kids passed to the probable molesters of the state’s Child “Protective” Services like Bob’s brother’s kids?

One notes that the FBI has been extremely poor at detecting troublemakers who act alone. This is a general truism of police work. Criminals get caught because they interact: they talk, and seal their fate; they associate with other criminals, and the capture of one gives investigators a powerful lever with which to pry loose the rest.

Or, to put it in the words of an old western movie, if you’re going to shoot, shoot. Don’t talk.

Notes

  1. You may have heard that phrase before. We were reminded of it by the Bureau’s reluctance to support a prosecution of Mrs Clinton for a more egregious version of an offense that it has arrested and helped imprison several for every year of the last decade, while snapping-to immediately in pursuit of the hackers that embarrassed The Party. The former alone might simply have been a case of how the Beltway operates increasingly on a Code of Hammurabi type law, with “different spanks for different ranks.” But in conjunction with the second, and various other activities, it’s clear that FBI is increasingly comfortable viewing itself as a partisan political police. People fear a military coup in the United States, but that is very unlikely; however, the Bureau’s higher echelons are starting to see themselves as the Praetorian Guard.

About Hognose

Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF).

Vietnam Sniper Study

Today’s article is a repost  from   our  deceased friend Hognose, owner  of Weaponsman.com.  Kevin, AKA Hognose passed away last year and as an ongoing tribute to his memory and excellent work we repost the  his works to help preserve it. 

Vietnam Sniper Study

In 1967, the Army got the idea to study whether, how, and how effectively different units were using snipers in Vietnam. They restricted this study to Army units, and conventional units at that; if SF and SOG were sniping, they didn’t want to know (and, indeed, there’s little news either in the historical record or in conversations with surviving veterans that special operations units made much use of precision rifle fire, or of the other capabilities of snipers).

Meanwhile, of course, the Marines were conducting parallel development in what would become the nation’s premier sniper capability, until the Army got their finger out in the 1980s and developed one with similar strength. The Marines’ developments are mentioned only in passing in the study.

Specific Weapons

The study observed several different sniper weapons in use:

  • ordinary M16A1 rifles with commercial Realist-made scopes. This is the same 3×20 scope made by Realist for commercial sale under the Colt name, and was marked Made in USA. (Image is a clone, from ARFCOM).

realist11

  • Winchester Model 70s in .30-06 with a mix of Weaver and Bushnell scopes, purchased by one infantry brigade;
  • two versions of the M14 rifle. One was what we’d call today a DMR rifle, fitted with carefully chosen parts and perhaps given a trigger job, and an M84 scope. The other was the larva of the M21 project: a fully-configured National Match M14 fitted with a Leatherwood ART Automatic-Ranging Telescope, which was at this early date an adaptation of a Redfield 3-9 power scope. (Image is a semi clone with a surplus ART, found on the net).

M21 ARTR

The scopes had a problem that would be unfamiliar to today’s ACOG and Elcan-sighted troopies.

The most significant equipment problem during the evaluation in Vietnam was moisture seepage into telescopes. At the end of the evaluation period, 84 snipers completed questionnaires related to their equipment. Forty-four of the snipers reported that their telescopes developed internal moisture or fog during the evaluation period. In approximately 90 percent of the cases, the internal moisture could be removed by placing the telescope in direct sunlight for a few hours.

The leaky scopes ranged from 41% of the ARTs to 62% of the Realists. The Realist was not popular at all, and part of the reason was its very peculiar reticle. How peculiar? Have a look.

Colt realist 3x20 scope reticle(A later version of this scope, sold by Armalite with the AR-180, added feather-thin crosshairs to the inverted post. The British Trilux aka SUIT used a similar inverted post, but it never caught on here).

The theory was that the post would not obscure the target, the way it would if it were bottom-up. That’s one of the ones you file away in the, “It seemed like a good idea at the time,” drawer. Theory be damned, the troops hated it.

The use of the rifles varied unit by unit.  Two units contemptuously dismissed the scoped M16s, and wouldn’t even try them (remember, this was the era of M193 ammo, rifles ruined by “industrial action,” and somewhat loose acceptance standards; the AR of 20145 is not the AR of 1965). The proto-M21s came late and not every unit got them. It’s interesting that none of the weapons really stood out, although the NATO and .30-06 guns were the ones used for the longest shots.

None of the weapons was optimum, but in the study authors’ opinion, the DMR version of the M14 was perfectly adequate and available in channels. The snipers’ own opinions were surveyed, and the most popular weapon was the M14 National Match with ART scope, despite its small sample size: 100% of the surveyed soldiers who used it had confidence in it. On the other hand, the cast scope rings were prone to breakage.

The biggest maintenance problem turned out to be the COTS Winchester 70 rifles, and the problem manifested as an absence of spare parts for the nonstandard firearm, and lack of any training for armorers.

Looking at all the targets the experimental units engaged, they concluded that a weapon with a 600 meter effective range could service 95% of the sniper targets encountered in Vietnam, and that a 1000 meter effective range would be needed to bag up to 98%. (Only one unit in the study engaged targets more distant than 1000 m at all).

Snipers were generally selected locally, trained by their units (if at all), and employed as an organic element of rifle platoons. A few units seem to have attached snipers to long-range patrol teams, or used the snipers as an attached asset, like a machine-gun or mortar team from the battalion’s Weapons Company.

An appendix from the USAMTU had a thorough run-down on available scopes, and concluded with these recommendations (emphasis ours):

Recommendations:
a. That the M-14, accurized to National Match specifications, be used as the basic sniping rifle.

b. That National Match ammunition be used in caliber 7.62 NATO.

c. That a reticle similar to Type “E” be used on telescopic sights of fixed power.

d. That the Redfield six power “Leatherwood” system telescope be used by snipers above basic unit level.

e. That the Redfield four power (not mentioned previously) be utilized by the sniper at squad level.

f. That serious consideration be given to the development of a long range sniping rifleusing the .50 caliber machine gun cartridge and target-type telescope.

(NOTE: It is our opinion that the Redfield telescope sights are the finest of American made telescopes.)

Note that the Army adopted the NM M14 with ART (as the M-21 sniper system) exactly as recommended here, but that it did not act on the .50 caliber sniper system idea. That would take Ronnie Barrett to do, quite a few years later.

Rifle_M21_2

The Effects of Terrain

Terrain drives weapons employment, and snipers need, above all, two elements of terrain to operate effectively: observation and fields of fire. Their observation has to overlook enemy key terrain and/or avenues of approach. Without that, a sniper is just another rifleman, and snipers were found to be not worth the effort in the heavily vegetated southern area of Vietnam.

In the more open rice fields and mountains, there was more scope for sniper employment. But sniper employment was not something officers had been trained in or practiced.

The Effects of Leadership

In a careful review of the study, we found that the effects of leadership, of that good old Command Emphasis, were greater than any effects of equipment or even of terrain. The unit that had been getting good results with the Winchesters kept getting good results. One suspects that they’d have continued getting good results even if you took their rifles away entirely and issued each man a pilum or sarissa.

Units that made a desultory effort got crap for results. Some units’ snipers spent a lot of time in the field, but never engaged the enemy. Others engaged the enemy, but didn’t hit them, raising the question, “Who made these blind guys snipers?” Sure, we understand a little buck fever, but one unit’s snipers took 20 shots at relatively close range and hit exactly nothing. Guys, that’s not sniping, that’s fireworks. 

The entire study is a quick read and it will let you know just how dark the night for American sniping was in the mid-1960s: there were no schools, no syllabi, no type-standardized sniper weapons, and underlying the whole forest of “nos” was: no doctrine to speak of.

Vietnam Sniper Study PB2004101628.pdf

Vietnam Sniper Study

About Hognose

Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF).

More Belt Fed: A Reader Shares His H&K23e

After the last post with videos of me  firing the H&K21   GPMG,  a readers has checked in adding some detail and sending some video of his 5.56mm HK.  After mentioning how I would like to try one in 5.56mm we get the next best thing.

Will,  one of the readers that found us through the Hognose at weaponsman.com, (RIP) joined the tet-a-tet in the comment sections and shared some video of his gun in action.

Will’s gun is obviously a newer model configured to be infinitely more useful in a fight in modern times.  You can see the control ability and recoil  from the 556 variant and compare to the videos I posted earlier.

 

I wanted to edit in to add some  words from Will about the gun  above.

“Shawn, thanks for posting this. Some details on the gun: it’s a Michaels Machines MM23E, which is not quite a true E spec gun.

Most notably, it uses a hybrid barrel that has the E extractor cutout but also the non-E safety mechanism. Both the HK21 and HK21E include a safety mechanism to prevent the gun from firing while the barrel is not locked into the receiver. On the HK21 a small pin sticks out of the rear of the barrel and interfaces with a matching indentation on the bolt face. If the barrel is unlocked, the pin prevents the bolt from going into battery.

On an E gun, a pin sticks out the side of the barrel opposite the barrel handle. When the barrel is unlocked, this pin prevents the charging handle from releasing.

You can use German E barrels on a MM21E or MM23E, but you have to remove the safety pin, which is a little scary. If you fire the gun while the barrel is not locked, it will fly down range and the barrel handle will tear off the front half of the receiver cage as it goes.

Like a real E, you can convert it to 7.62×51 by swapping the bolt, barrel, and feed mechanism, which can be done in a minute or two. German feed mechanisms work fine with the MM guns, supposedly. The bolt group is different, however, since it has a slot and ramp cut into it to actuate the trip lever for transferable sear packs. A real German 21/23E uses a one piece sear/trip lever, and isn’t compatible with a transferable sear.

As for Michaels Machines, owned by Mike Otte, I had a terrible experience, and am still having the occasional issue. They are very expensive guns with long lead times, but mine did not work well out of the box, had a multitude of finish and function issues like a canted front sight that was so far off to the side that I couldn’t get it on paper, and a botched job on my sear install in a 4 position burst pack. My feed mechanism is currently back with Otte since some of the parts are warping or wearing at an unusually high rate and causing jams, almost like the heat treat wasn’t quite right.

If I were to do it all over I’d let TSC build the gun out of a German 21E parts kit and HK91, which would cost twice as much but be as close to the real thing as possible, and undoubtedly work well.

Here’s a picture of the whole gun: 

 

I always take flak for changing to an AR style stock, but with the riser it gives the correct cheek weld with the optic, and also shortens up the length of pull to a more manageable distance, which brings the center of gravity rearwards to aid with offhand shooting”

 

A bit of an update, and a warning about doing business with Mike Otte:

After receiving the feed mechanism back and still having more issues, Otte and I had it out on Subguns. The full archived thread starting with my post can be found at:
http://www.subguns.com/boards/mgmsgarchive.cgi?read=881453

Pictures of the poor workmanship are also in that thread, and you can see exactly how Otte treats his customers (quite poorly, if you do not want to read the whole thing).

Then, at shot show, my business partner came upon Otte in the B&T booth where he was telling a B&T representative (who happens to be a close friend of mine) and two Arizona State Troopers about my gun while ridiculing me. Unfortunately I was not there, but my business partner got into a heated discussion with Otte, and was able to record him admitting that he didn’t build my gun; it was sourced out to a third party and that batch may actually have real problems.

Once Otte left, the two AZ troopers came over and told my friend that they both owned MM23Es that didn’t work originally, and required extensive modifications by RDTS to make them run.

After Shot Show and the confrontation with my business partner, Otte finally agreed to replace my gun. He has had it since then, and I do not know when I will get it back. Please keep in mind I paid in full for it in August 2016, so it’s coming up on the 2 year mark.

 

A Short History of Chrome Bores

Again this week we have a post from our friend Kevin O’Brien, owner and author of weaponsman.com.  Kevin AKA Hognose, passed away earlier this year and in a back up effort we will be running  “The Best of weaponsman”  which could be every technical article he  wrote. 

 

For some 500 years it’s been known that rifling would impart spin and therefore stabilization to a ball or bullet. Spiral grooves probably evolved from straight grooves only intended to trap powder fouling; by 1500 gunsmiths in Augsburg, Germany, were rifling their arquebuses. This gave rise to an early attempt at gun control, according to W.S. Curtis in Long Range Shooting, An Historical Perspective: 

In the early 16th Century there are references to banning grooved barrels because they were unfair. Students of the duel will recognize this problem arising three hundred years later.

Curtis, 2001. Curtis notes that why rifling was twisted is unknown, and that it may have been incompletely understood. He has quite a few interesting historical references, including one to a philosopher who explained that if you spun the ball fast enough, the demon (who dwelt in gunpowder, which was surely Satan’s own substance) couldn’t stay on and guide your ball astray. (Curtis’s work is worth beginning at the beginning, which is here).

By the mid-19th Century, the Newtonian physics of the rifled bore had been sorted out, the Minié and similar balls made rifled muskets as quick-loading as smoothbores, and the scientific method allowed engineers to test hypotheses systematically by experimentation. So smoothbores were gone for quite a while (they would return in the 20th Century in pursuit of extreme velocities, as in tank guns).

Rifling had several effects beyond greater accuracy. It did decrease muzzle velocity slightly, and it did increase waste heat in the barrel. The first of these was no big deal, and the latter was easily handled, at first, by improved metallurgy. But rifling also helps retain highly corrosive combustion by-products in the bore; and corrosion was extremely damaging to rifling. Pitted rifling itself might not have too much of an effect on accuracy (surprisingly), but the fouling that collected in the pits did. Corrosion also weakened the material of barrels, but most military barrels had such great reserves of strength that this was immaterial, also.

Fouling and pitting have been the bête noire of rifles from 1498 in Augsburg to, frankly, today. A badly pitted barrel can only be restored by relining the barrel, a job for a skilled gunsmith with, at least, first-class measuring tools and a precision lathe with a long bed. Relining has never been accepted, to the best of our knowledge, by any military worldwide.

Chrome Plating is Invented: 1911-1924

One approach has been to use corrosion-resistant materials for barrels, but that has been late in coming (late 20th Century) because it is, of course, metallurgy-dependent. Early in the 20th Century, though, American scientists and engineers developed a new technology — electroplating. George Sargent, of UNH and Cornell, worked with chromium as early as 1911, and Columbia scientists developed a commercially practical process of using electrodes to deposit chromium by 1924. Meanwhile a New Jersey professor worked with a German process.

The two groups of professors formed start-ups, the Chemical Treatment Company and the Chromium Products Corporation. At this point, chrome plating has not been applied to firearms. Electroplating had been used for guns for decades, of course, but that was nickel plating — eye-pleasing, but soft and prone to flaking, not suitable for bores, and not remotely as corrosion-resistant as chromium.

(This article is rather long, so it is continued after the #More link below. We next take up the application of this process to rifle bores).

Chrome comes to bores in the lab: 1925-32

One thing that had held chrome plating back was lack of a practical quality control method. George Dubpernell discovered a practical test almost by accident: chrome would adhere to copper, but copper would not adhere to chrome. This was later supplanted by NDT methods, but it was essential to the growth of chrome in industry.

Olin’s and Schuricht’s patent of 1932 (not 1935, a rare error in Emerson),  US Patent 1,886,218, applied chrome plating to small arms and sporting weapons’ bores. They applied for the patent in 1927, and note, as is now well known, that bores must be made slightly oversized to account for the dimensional changes from chrome deposition. They also, interestingly, saw chrome plating as a way to restore worn rifling and eroded barrels. We’re unaware of any such use being brought into practice in the intervening decades.

Meanwhile, in 1937, T.K. Vincent noted that:

Chromium plating of small arms barrels results in longer accuracy life. However, the cost of plating is excessive compared to the results obtained.

The longer accuracy life results from taming the bugbear of bore erosion. By 1942, in a thorough study of bore erosion of guns large and small (from 3″ naval guns to small arms),  Burlew noted a report by Russell that considered chrome plate a “bad” material from a bore-erosion standpoint, except “when made very adherent”; in that case it was an “excellent” material, roughly five to nine times better than ordinary plating. Chrome-plated steel barely edged out bare steel, and all beat exotic metals like Inconel and Monel; the least erosion was found in the chrome-plated barrels with the thinnest chrome plating (0.0005″), although all these tests were of a 12″ naval gun, and their applicability to small arms might not be direct or proportional.

The technology of chrome plating continued to advance, even as weapons designers struggled to bring the technology’s benefits to bear on practical small arms.

Adoption of chrome by the world’s militaries — early adopters

The Empire of Japan was the earliest nation to chrome the bores of its rifles. The Japanese had different reasons, perhaps, than other nations. In Japan, supply of high-quality steel was insufficient to wartime requirements. This is especially true after 1940, when the United States imposed sanctions on the island nation, which depended on imports for almost all resouces; and even more true as unrestricted submarine warfare, which was ordered implemented even as the Pearl Harbor strike force was recovering on their carriers, began to strangle the home islands.

Casting about for a way to work with the second-rate steels they had, the engineers at Sagami Arsenal, which was used for ammunition storage and for war production (Japan’s only 100-ton tank was built here; it was too heavy to move to the seaport for deployment) set upon a 1937 patent. They concluded that chrome-plated mild steel could substitute for some high-speed and high-carbon steels, and from 1940 that’s what Japanese engineers did. The history of a Japanese firm explains:

The Japan Science Council reported then Government to recommend the policy to apply hard chrome plating on the low grade steel as the alternative to high grade one, such as special steel or high-speed steel, under the difficult external trade conditions to get them, the invention, Patent No.131175 (1937), “the method to deposit hard and thick metal chrome plating” by Minoru Araki, the former president of Company, being as the technical foundation. It was followed by the request to establish a specialized company of hard chrome plating (industrial chrome plating) from National Headquarters of Aviation, Sagami Arsenal, and customers.

As a result, the next rifle adopted by Japan, the Type 99 Arisaka 7.7mm rifle, had a chrome-plated bore. As David Petzal writes for Field and Stream, they were “the first military barrels ever to have this feature.”

The industrial and materials-science reasoning behind Japanese chroming is missing from most US sources. Gordon Rottman (a fellow SF veteran) writes that , “the Japanese had the foresight to produce the type 99 with a chrome-plated board to prolong barrel life, ease cleaning, and protect it from tropical rust.”

In addition to the Type 99s, all of which were intended to be made with chrome-lined bores, all Type 100 submachine guns, some late Type 38 6.5mm Arisakas, and some late Type 14 “Nambu” pistols had chrome-lined bores. By late in the war, ever more serious materials shortages meant that chrome bores were one of the features deleted from late production guns (like such Type 99 features as a monopod).

The United States initially chromed only large-caliber artillery bores. From Navweaps.com:

In the 1930s, the USN started to chrome plate the bores of most guns to a depth of 0.0005 inches (0.013 mm). This was “hard chrome,” which is not the kind that you find on your father’s Oldsmobile. This plating increased barrel life by as much as 25%. The plating generally extended over the length of the rifling and shot seating. Chrome plating has also been found to reduce copper deposits.

All along, as a large body of scientific papers at DTIC reveals, US small arms developers continued to work on chrome for small arms. US engineers were aided in this by their very great extent to which chrome was being used in the automotive industry. Springfield Armory developers would have had access to many papers being produced at the same time by the SAE, and Springfield of course worked closely with the developers, themselves, of chrome industrial processes.

But chrome was not standardized for US small arms bores until after World War II — in fact, not until the mid-1950s, well after Japanese and Russian adoption of the technology. As we’ve recounted here before, the first US weapon to be manufactured new with a chrome bore was the M14 rifle. Around the same time, chrome bores were used in developing a 7.62 mm NATO conversion kit for the Browning light machine guns, and replacement barrels that were manufactured for Legacy weapons like the M1 rifle, started to be manufactured with chrome bores as well.

Because chrome bores lost some definition in the rifling, and therefore some accuracy, National Match rifles continue to be produced with standard bores. But the advantages of chrome in the field could not be overlooked.

The M16 rifle was initially produced without a chrome bore. There are two reasons for this: first, the M16 was a product of a private industry initiative, and not the usual Army development system. The disastrous fielding of the M-16, with the bare bore combined with very poor maintenance practices and some units, led to the Army adding a chrome chamber, and then finally a chrome bore to the weapon.

Another assembly of the M-16 was chromed, and this led to a lot of problems. The part in question was the entire bolt carrier group. Early on, a number of the bolts and bolt carriers failed. This turned out to be due to metallurgical problems, specifically with heat treating (that will sound familiar to anyone who has followed the M14 history), the deficiencies of which were masked by the plating, and also with hydrogen embrittlement of the steel carrier during the chroming process. The specification was changed to require the bolt to be Parkerized, except for its internal expansion chamber, and the inside of the bolt carrier key, which are still chromed (chroming only a single surface of a part does not risk hydrogen embrittlement).

Early chrome BCGs that were properly heat-treated and passed testing were allowed to remain in M16A1s by the Army, but they were not allowed to be deployed OCONUS. The reason given (in the M16 maintenance manual, TM9-1005-319-23&P) is simply to prevent glare off a chrome bolt carrier from exposing soldiers’ positions.

The USSR‘s reasons for introducing chrome plating (whether for corrosion control, ease of cleaning, or metallurgy) are unknown to us, but extensive collector interest makes it clear when the feature was added: 1950. No known 1949 SKS or AK rifles have chrome bores, some 1950 models do, and almost all 1951 and subsequent guns do. Chinese AK and SKS rifles were produced with chrome bores from their introduction in 1956. Some satellites’ bores were not chromed, notably Yugoslavia’s pre-1970s. (Yugoslavia was technically not a “satellite,” but it was a Eurasian communist country).

For practical purposes, this means that all Soviet and Chinese spec AKs will have chrome bores. In addition, gas pistons are also chromed. This greatly facilitates cleaning, and prevents corrosion in a highly corrosion-prone part of the system.

Russian small arms of larger caliber, including the 37mm tube of the RPG-7V, are also chromed.

Adoption of chrome by the world’s militaries – later adopters

Belgium, a small country that looms large in world firearms exports thanks to FN, was not an early adopter of chrome bores. The entire production of the FN-49, including all ABL, SAFN, and AFN rifles, left the FN factory with conventional steel bores. Much later, metric pattern FALs received, first, chrome chambers, and later chrome bores. What makes FN interesting enough to comment on here is their  use of chrome extended to the internal parts of their MGs and the insides of their receivers, making MAGs and Minimis very easy to clean.

US variants of these FN guns don’t have these parts chromed. The initial MAGs and Minimis purchased using using special funding vehicles by select US special operations units, had these features. In subsequent US production, the chroming was eliminated, and those parts of the M240 and M249 are Parkerized. We don’t know if this was done to save money, because the Army simply preferred the Parkerized coating, or because of the Army’s bad experience with chromed bolts on the M16A1.

Britain adopted chrome bores well after World War II, including some retrofits like the L4 Bren Gun from at least the L4A4 version to the final L4A9. As noted above, Britain’s inch-pattern FALs did not receive chrome bores.

Chrome chamber vs Chrome bore

Industrially speaking, each of these had its own pros and cons. Chroming the whole barrel was more expensive, increased demands for both manufacturing and inspection precision, required the rifling to be cut slightly oversize (to allow for the chromium deposition), and led to much greater waste. Chroming the chamber was a compromise that enhanced extraction — a sticky problem with many automatic arms — without the costs and problems associated with full-length bore chroming.

But the US experience showed that half a loaf (chroming the chamber only) didn’t get the job done. While the chamber became very resistant to corrosion, GI’s inspection of the bore often stopped with a glance in the chamber area, and if the chamber was gleaming, they’d assume the rifle was good to go — eveb as combustion byproducts and deposits ate away at the rifling.

Meanwhile, chrome bores let the manufacturers do things that were difficult or even impossible with conventional manufacturing processes. As noted above, the Japanese were able to use chromium plating to substitute for lack of chromoly steel. In the USA, Springfield Armory discovered that by slowly withdrawing the barrel, chamber first, from the chromium bath they could create a squeeze-bore effect due to the higher deposition of chrome on the parts of the barrel that were in the chrome bath longer. (Methods of altering the depth of chrome depositions produced at least two patents, 2,425,349 and 2,687,591; the second is Springfield’s process).

Chrome’s cost rises

In the 1970s, the chost of chromium suddenly went through the roof: the two greatest producers, Rhodesia and the USSR (ironically, two defunct nations, today) were locked out of the US market, the former by sanctions and the latter by international politics. (Note that around 1974 the styles of American cars began to use less chrome plate and more body-colored and black molding. This fashion was driven in part by costs).

Today, the biggest driver of rising plating costs is new environmental regulations. Chromium, like most metals, is something you really don’t want to breathe in.

Quality chrome plating is still expensive, and cheap plating produces a lot of waste. Some gun parts makers have chosen to, essentially, ignore the waste and ship products with poor (or zero!) nondestructive testing and inspection, sacrificial sample examination, or other valid QC.

Chrome plating today & tomorrow

Plating has to fight to maintain its place vis-a-vis other anticorrosion technologies, including noncorrosive metals (i.e. stainless steel) and superior steel coatings like Melonite, but it has a very strong position as an erosion fighter, particularly in barrels subject to high temperatures (think automatic fire).

Some scientists are working on electroplating as a means of additive manufacturing. Laugh if you like, but the plating industry of today was entirely based upon laboratory discoveries.

And gun engineers continue to apply new kinds of chromium treatment to bores. A recent patent application by Rheinmettal covers depositing a different thickness of chrome in the lands and the grooves of a rifled barrel.

One of the biggest changes is that a chrome-plated bore, if made with sufficient care, may be as accurate or more accurate than a bare bore. (For example, SAK manufacture M16 replacement barrels seem to outshoot many target barrels). But this may not be as big a change as you think. According to Emerson, in 1962 Springfield Armory made a small quantity of chromed National Match barrels. They discontinued the practice not because the barrels were bad, but because they were much more expensive to make than bare barrels, and they were not any better. But they were atdid fully comply with national match standards at the time.

Chrome-lined barrels are currently the standard in military small arms. This will change if and when something better comes down the pike – and not before.

References

Burlew, John S. The Erosion of Guns, Part One: Fundamentals of Ordnance Relating to Gun Erosion. Report No. A-90 Progress Report. Washington: National Defense Research Committee, 8 Sep 42. Retrieved from: http://www.dtic.mil/dtic/tr/fulltext/u2/a422462.pdf

Burlew, John S. The Erosion of Guns, Part Two: The Characteristics of Gun Erosion. Report No. A-91 Progress Report. Washington: National Defense Research Committee, 31 Oct 42. Retrieved from: http://www.dtic.mil/dtic/tr/fulltext/u2/b280242.pdf

Curtis, W.S. Long Range Shooting, An Historical Perspective. Research Press, 2001. Retrieved from: http://www.researchpress.co.uk/longrange/lrhistory.htm

Dubpernell, George. History of Chromium Plating. Products Finishing magazine, 13 Nov 12. Reprint of Plating & Surface Finishing from 1984. Retrieved from: http://www.pfonline.com/articles/history-of-chromium-plating

Emerson, Lee. M14 Rifle History and Development. Online Edition, 2007. 

GlobalSecurity.org. Sagami Depot, Japan. n.d. Retrieved from: http://www.globalsecurity.org/military/facility/sagami-depot.htm

Koka Chrome Industry Ltd., Company History. n.d. (2011 or later). Retrieved from: http://www.koka-chrome.co.jp/en/company/history.html

Olin, John, and Schuricht, Alfons. Gun barrel and process of finishing the same. Washington, 1932: US Patent No. 1,886,218. Retrieved from: http://www.google.com/patents/US1886218.

Rottman, Gordon. Japanese Army in World War II: the South Pacific and New Guinea, 1942–43. 2005: Osprey Publishing. (p. 36).

US Army, Technical Manual: Unit and Direct Support Maintenance Manual (Including Repair Parts and Special Tools List): Rifle, 5.56mm M16A2; Carbine, 5.56mm M4; Carbine, 5.56mm M4A1. Washington, DC, 9 Apr 97

Vincent, T.K. Development of Chrome Plating of Guns. Abstract only (have been unable to find the full text). Aberdeen Proving Ground: Ballistics Research Labs, 1937. Retrieved from: http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0701179

About Hognose

Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF).

 

5 Reasons for the AK’s Legendary Reliability

 

Since the untimely passing of our friend, Kevin  AKA Weaponsman, we will be running  “the best of weaponsman.com” in his memory.

 

5 Reasons for the AK’s Legendary Reliability

AK-47The Avtomat Kalashnikova obrazets 1974g and its successors have an enviable reputation for reliability, especially under adverse conditions. There are a number of reasons for this, and we’ll go into them in some depth here. First, though, let’s say what is not a cause:

  • It’s not because of blind luck.
  • It’s not because the weapon is orders of magnitude better than its worldwide competitors. Indeed, by the end of WWII a very high standard of reliability had come to be expected, and weapons that did not meet this standard were mercilessly eliminated, like the Johnson M1941 and the Tokarev SVT.
  • Mikhail KalashikovIt’s not because Kalashnikov the man had genius that was lacking in other men. His competitors in the field, from Browning, to the Mauser-werke engineers of the 1940s to Stoner, were certainly men of genius as well. (Heck, so were Tokarev and Johnson). He’d have been the first to tell you he was just a thinking engineer.
  • It’s not because of breakthroughs. Almost every feature of the AK is recycled from somewhere else. What Kalashnikov did was synthesize them in a new way.

The Kalashnikov rifle is not, in fact, a universally superior design. Compared to its worldwide competitors (the FN SAFN and FAL, the CETME and G3, the M14 and M16 series, to name the most important), it is less accurate, less flexible/adaptable, and less ergonomic than every other. It offers less practical range than any other; and at the other extreme of range, it is the worst bayonet handle. It weighs more than some, has the heaviest magazines by far, and has an inferior weight-to-firepower ratio to most. It is inaccurate from the shoulder in full-automatic fire, yet it is designed to be fired, preferentially, on full automatic.

The strengths of the AK have overcome these deficiencies to make it incredibly common worldwide. Those strengths, compared to its competitors, include a somewhat lighter weight of ammunition, a larger standard magazine, great simplicity of operation and ease of manufacture, and that vaunted reliability, perhaps its most salient characteristic.

Design features of the AK which contribute to its reliability include:

1. Simplicity

The AK is almost as simple as a hammer. It is simple to build and manufacture (we’ll go into some specifics below). It uses no space-age materials, not even any aeronautical technology, just 19th-Century steel and iron and wood. (Much later, Kalashnikovs would have composite magazines and composite furniture. The US put composite stocks on BARs by 1944, and had them ready for the M1 and M14 in the 1950s, but an AK would not have a composite stock in its home nation for another forty years). There is no advanced machinery needed to produce an AK — indeed, one can be built (and they have been built) with hand tools and no precision measuring equipment, not even a micrometer. The rifle itself has no parts that cannot be filed, ground or machined from steel, or hammered from sheet metal, or riveted or welded from parts made this way. Most auto repair shops have the tools needed to build an AK, apart from rifling the barrel; the necessary materials are in the same shop’s scrap pile.

The AK’s operating system is simple and proven, a long-stroke gas piston system and a rotating bolt. Unlike the dainty bolt of the AR system (lifted itself from the M1941 Johnson) with its 7 precision locking lugs (and one false lug on the extractor), the AK bolt has two locking lugs, oversized, overstrong, and remarkably tolerant of undersized contact patches with the locking recesses of the trunnion. (Factory AKs have wide disparities here, especially those made by some of the more slipshod non-Russian, non-Chinese factories. The guns all seem to headspace correctly, operate normally, and fire reliably).

The AK does have one part that is a highly complex weldment: the magazine. The magazine and the feed path in general is very simple, straightforward, and repeatable, which is why the mag clearly got a lot of engineering hours. Gun designer David Findlay, who’s worked at Remington, Marlin, H&R 1871, and Smith & Wesson, says**:

Feed-system design, though, is one of the most important aspects of any weapons performance. A great deal of testing must be done to ensure good performance. Small variations and subtleties in magazine dimensions can have enormous impact on gun reliability and function.

Findlay wrote these words in explaining the engineering of the feed path of the Thompson Submachine Gun, but they’re generally applicable, and go a long way to explaining why Mikhail Kalashnikov lavished so much care on the magazine design. The fact that the receiver of the AK has received many modifications, but that the only change to the magazine is in reinforcing ribs and later magazine-body materials seems to hint he got it right.

An old engineer’s quip is that the designer’s objective is to “simplicate and add lightness.” (This has been attributed, among others, to automotive engineer Colin Chapman and aerospace engineer Burt Rutan). Mikhail Kalashnikov started off by “simplicating” most of the potential for trouble out of his design. (He didn’t make “adding lightness” a priority).

2. Environmental protection

Every designer has long known that foreign matter — mud, dust, and what have you — are the bitter enemies of reliable function in the short term, and that corrosion, rust, is the long-term destroyer of gun reliability. If you examine an AK you will see that it’s hard for foreign matter to intrude into, say, a dropped rifle. The safety, modeled loosely on that of the Remington Model 8 (a Browning design), does double duty in sealing the gap between the receiver and the nonstructural receiver cover. In operation, the charging handle, which is part of the bolt carrier, reciprocates in the open slot that the safety/selector seals shut. That seal and the lack of other large entrees into the receiver keep the interior clean.

Unlike Browning or Stoner, Kalashnikov was limited by the Soviet industrial base; he couldn’t call out exotic materials or sophisticated protective treatments, so early AKs were all steel and rust blued, an attractive finish that was weak at preventing corrosion. Some critical parts, though, notably the gas port area, the gas piston, and the bore, received hard chrome plating, and the weapon is designed in such a way that rust or pitting on other parts just does not matter in terms of reliable function or accuracy. It’s not unusual to find AKs in the field with all kinds of surface rust and pitting on their exteriors, only to find that the vitals, protected by chrome plating, have held up, and the guns still shoot within the modest (and sufficient) standards of a new AK.

3. Lack of small, dainty (and fragile) parts

A field-stripped AK contains nothing you’ll need to grope for if you drop it in tall grass (or mud, or a stream) in the dark. The pieces are big and robust, deliberately so, and this philosophy extends to the internals.

heartbreak ridge AK47 2

Nothin’ dainty about it.

The story of the development of any weapon you care to name involves interesting (and sometimes distressing) breakages. The FN, for example, was prone to firing-pin failures (the answer, which took the experts of three countries to fix, was to reduce the hardness of the part, as measured on the Rockwell C scale, and to shot-peen its surfaces: problem solved). The very first AR-10 tested by the US government had a bullet emerge from the side of the barrel in testing, not exactly a confidence-builder. (They gave up on an AL alloy barrel with a steel liner, then, which neutralized the gun’s weight advantage over the extant M14). Indeed, the AR-10 had terrible problems well into its development and production, and the Portuguese were still solving problems with it during their colonial wars in the 1970s. Many of those same problems, and a set of new ones, struck during development and production of the M16. The AK presumably had problems with these, but because the information was closely held at the time, archives have not fully opened, and most of the principals passed on without leaving technical memoirs, we know about only a few of them (for example, the failure of the first model stamped receivers, which caused a change to a machined-from-billet receiver).

The internals, though, seem to have been robust from the very beginning. Kalashnikov’s point of departure was the Garand trigger group, which itself borrowed from Browning. (Stoner would choose that same point of departure). This is part of the brilliance of the design: he wasn’t inventing for the sheer joy of inventing, but to make something that worked. That means, where he didn’t have a way of doing it better than someone else, he borrowed happily.

Borrowing aside, the Kalashnikov’s departures from Garand practice (apart from those required to render the weapon selective-fire, and to improve the Garand’s sub-optimal safety) showed a lot of interest in making things sturdier. The hammer spring, for instance, is made of two wires coiled together, giving some small redundancy; it also does double-duty in the AK as the trigger return spring.

4. Minimal use of tight tolerances

There are some parts of a gun that absolutely must fight tightly to ensure accurate, safe, and yes, reliable operation. On the AK, almost all of those are permanently assembled at the factory (the barrel into the trunnion, for example). The trigger mechanism is designed with a lot of slop and play in it, which is why AKs have that typically very long, smooth trigger pull with a surprise let-off (SKSes are similar), but it isn’t that way to manage the trigger pull: it’s there so the mechanism will be positive and safe the first time and the 1,000,000th time.

The only moving parts with truly tight tolerances are the fit of the bolt lugs into the trunnion, which affects headspace. For safety and accuracy headspace has to be right on. But the non-bearing surfaces in the trunnion are opened up enough that dust and dirt has somewhere to pack into, other than interfere with the tight fight of bolt to trunnion. John Garand considered the wise use of tolerances key to the legendary reliability of the M1*. Like the AK, its only critical tolerances in the operating mechanism come from the interface of the lugs of the rotating bolt with the mating recesses of the receiver.

5. Use of very loose tolerances everywhere else

Garand deliberately eschewed the use of a bolt carrier in place of an operating rod. He considered the competing bolt carrier and tipping bolt design (as used in Tokarev, Simonov and FN rifles) more troublesome both in production and in service because they had more critical tolerances. While the AK uses a bolt carrier, its fit to the bolt and receiver is if anything even less critical and looser than Garand’s op-rod.

What Rayle (and Garand) thought of as an innate flaw in bolt-carrier vs, op-rod systems, the need for precision tolerances both on the locking/headspacing feature of the bolt and its receiver, and also on the interface of the bolt with the bolt carrier, turns out to be an innate flaw in the Browning (Tokarev, Simonov, Saive, Vervier, etc). tipping bolt. The AK’s bolt can interface with its carrier just as loosely as the M1s does with its operating rod, with no harm to the functioning of the rifle.

This is not to say that nothing on the AK is manufactured with precision. (That would be the STEN). The beauty of the AK, from an engineering design viewpoint, is that nothing is manufactured with unnecessary precision.

To Sum Up

aklgcolcopyThese things, taken together, suggest that the AK is narrowcast at its original role as a submachine gun replacement for the semi-literate peasant conscript army of a nation lacking depth in precision manufacturing. It was the perfect gun for the Red Army in World War II, even if it came a little too late. It was also, therefore, the perfect gun for the continuation Soviet Army.

Unlike the service rifles of the USA or Germany, or the first-generation battle rifles of the West in the 1950s, the AK was manufactured without an excess of precision which limited its adaptability as, say, a sniper rifle. (The AK’s then-unique use of an intermediate cartridge also did this). But it suited Soviet doctrine of mass attacks and mass fires well. Unlike the NATO rifleman, the Soviet soldier, although instructed in semiautomatic fire on ranges, was also extensively drilled in live-fire obstacle courses, and was expected to run them firing on full-automatic, from the hip. He was the heir of the submachine-gun battalions of the Battle of Berlin, and planned to fight the same way, as mechanized infantry guarding the flanks and securing the obstacle-ridden forests and towns to enable the great tank attack. Hence, the first click off safety on an AK is full-auto, contrary to every successful NATO selective-fire rifle.

The same adaptations, design decisions, and production practicality that made the AK a perfect replacement for Ivan’s retired PPSh submachine guns, made the AK a perfect weapon for terrorist groups, “national liberation” movements, and under-resourced armies of newly free colonies worldwide.

Like the Mauser before it, the AK is a universal gun. And like the Mauser, the AK will be with us until something better supplants it. And “better,” in this case, will be defined by history and by nations, not necessarily by gun experts.

 

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* John Garand’s comments come from Rayle, Roy E. Random Shots: Episodes in the Life of a Weapons Designer. 

** Findlay, David S. Firearm Anatomy: Book I: The Thompson M1A1 Submachine Gun. p. 76. San Bernardino, CA, 2013: Findlay, David S.

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Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF

The site owner is a former Special Forces weapons man (MOS 18B, before the 18 series, 11B with Skill Qualification Indicator of S), and you can expect any guest columnists to be similarly qualified.

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