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.

This entry was posted in Foreign and Enemy Weapons, GunTech, Industry, Rifles and Carbines on by .

About Hognose

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.

Our focus is on weapons: their history, effects and employment. This is not your go-to place for gun laws or gun politics; other people have that covered.

The Best of “Weaponsman” Part 1 (M16A1 Maintenance Survey in Vietnam)

As we reported last week and as everyone familiar with this website knows, our friend Kevin O’Brien, AKA “Hognose”, passed away. Kevin was a good friend of looserounds and  we often shared info back and forth for a variety of gun related topics.    Not 100 percent  sure that weaponsman.com has will be available in the coming years I will be running a weekly ( or maybe more or less often) “best of post” of some of Kevin’s best stuff  from his website to save  it for all and as a tribute to our friend.

 

M16A1 Maintenance Survey in Vietnam

By Kevin O’Brien ” Hognose”

We’re looking at a declassified report from the US Army Weapons Command in 1968. The report is available to subscribers to Small Arms of the World in their archives. And we came across the following little gem, which we’ve already served with several Vietnam-SF buds. Emphasis ours:

The first USAWECOM survey team stayed in Vietnam from 21 October1965 until 2 December 1966. (4) While the primary purpose of the team (5) was to provide maintenance instruction to a nucleus of officers and men from each brigade, who would then teach their own units, direct support organizations wece also instructed.

The team taught maintenance in every major USARV unit except the 1st Air Cavalry Division. (6) Students brought their own weapons, magazines, ammunition, cleaning materials, and accessories to class. A detailed inspection of each student’s equipment revealed that with the exception of the weapons of the 1st Brigade, 101st Airborne Division, the 173d Airborne Brigade, and the 5th Special Forces, all the weapons were poorly maintained.

The footnotes (4) and (5) refer to the team’s report and describe the makeup of the team — led by an ordnance LTC with four experts from USAWECOM and three from Colt. Note 6 explains why the Cav wasn’t trained — they said they were having no trrouble with the M16A1, and asked only for instructors to work with its divisional maint battalion small-arms shop.

So what was jacked up about the GIs’ guns?

The most common faults observed were:

  1. Excessive oil on the weapon
  2. Carbon buildup in the chamber, bolt, and bolt carrier group
  3. Overloading of magazines with 21 rounds of ammunition
  4. Oil and grit inside magazines (frequently accompanied by lubricated ammunition); and
  5. Failure to replace worn or broken extractors and extractor springs.

Other deficiencies noted frequently were shortages of technical manuals, cleaning equipment, and repair parts, and a general lack of knowledge of the M16 rifle among officers and noncommissioned officers.

At first it may seem strange that soldiers were unfamiliar with their weapons, but you have to remember how this report fits into American small arms history. The M16A1 was a standard — in Vietnam, only. The rest of the Army still soldiered on with the M14, and an awful lot of people in Army Ordnance still had their noses out of joint that Westmoreland had ordered a lot of weapons that were Not Invented Here (the M14, like the M1 before it, was developed in-house by the Army). Some of them wanted the M16 to go away. Others wanted it to fail. Still others were captivated by the small-caliber, high-velocity concept and the M16’s brilliant ergonomics, and determined to help make it work. And many were of a type with Army men of all nations and all times: given a mission, intent on carrying it out.

We thought it was interesting that three airborne units (the 101st was still nominally Airborne at this time, although it would only have the name as n honorific by the time it left Vietnam) had few worries with their M16s, although it seems like the 1st Cav didn’t either. So why were the airborne units squared away, when most of the legs weren’t? Turns out that it wasn’t due to the higher quality of troops in the supposedly all-volunteer paratroop units, but had a more mundane explanation:

The 1st Brigade, 101st Airborne Division, the 173d Airborne Brigade, and the 5th Special Forces were the only units surveyed that had received training with the M16 for a significant period of time prior to deployment to Vietnam. Men in other units had been given training in marksmanship but little or no instruction in care and cleaning of the rifle.

On a follow-up visit, intended to cover maintenance of the very maintenance-intensive XM148 grenade launcher, a subsequent team discovered that many of the M16s turned in for maintenance (which might not be typical of all M16s in the field; a working weapon doesn’t get turned in for maintenance) had pitting in the chamber. They did the math and came up with a statistical prediction that 10% of all 16s in Vietnam would need a replacement barrel every three months. That correlated nicely with field complaints of extraction and ejection problems. One answer was to add chrome plating to the chamber (later, the whole bore) of all M16A1 rifles, and this report seems to be where that suggestion was first committed to official writing. This suggestion was not exactly rocket surgery: at the time, the Russians had been doing it for 20 years.

The chrome chamber weapons have “MP C” or “C MP C” markings on their barrels. The later Vietnam-era chrome bore weapons are marked “C MP B.” After the war, the marking changed to “C MP CHROME BORE” and that’s what most of the small supply of surplus M16 barrels say. The bore chroming is not a sign of a particular model of M16, it’s simply a running change, one of many hundrendrds

A lot more interesting stuff in this report. There is a CYA aspect to some of it, for sure, but it’s a window into a problem (M16 Jamming, circa 1966) of which much has been written, usually without reference to primary sources like this.

About Hognose

Kevin  O’Brien  was a Former Special Forces 11B2S, later 18B, weapons man. (Also served in intelligence and operations jobs in SF).

Kevin O’Brien ( AKA “Hognose” of weaponsman.com ) Our Departed Friend

Tonight we learned something we had feared was coming over the last few days.  Kevin O’Brien,  known to most of his readers as Hognose, has passed away.  Kevin’s brother updated his brother’s website a few days ago with news that his brother was in bad condition in the hospital and gave an email address for people who knew Kevin more than as a reader of his website.  The details received privately had us greatly worried.  With no sign of recovery his family did what most would want their families to do, let Kevin pass on peacefully.

Kevin’s website weaponsman.com was started almost at the same time as this website, and we have been following him since the start and vice versa. Kevin wrote about us in his “Weapons website of the week ” column and the track back is how we found him.   He said many nice things about our work on his website and it was much appreciated at a time when this site was a two man show.

I got to know Kevin a little more personally via emails thanks to the introduction made by Daniel. I often would send Kevin copies of pictures I  or one of the others took at industry shows and he was usually the first person I shared new gun news with or inside info. I was glad to get to know him better.

If you have not read his website, please do so.  His brother has announced he will take it down soon and much will be lost. If you are not one of his regular readers, you don’t know what you are missing.  In my opinion his was the best gun blog on the web.  He did not do reviews or have the same format as us, but his site was a true blog and it is very  entertaining, It is filled with vast technical data on many weapons and has stories told from Kevin’s long  Army career as he was a Special Forces ( Green Beret).  The name of the site came from his job in the SF “weaponsman” among other things he did in the Army,   “WeaponsMan is a blog about weapons. Primarily ground combat weapons, primarily small arms and man-portable crew-served weapons. 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.”

Some of his most darkly funny posts are the “when guns are outlawed then only  outlaws will have , knive, poison, trucks, pillows, gravity etc etc.,  He would often end those posts with something like “Hug your loved ones tight as you never know when it may be the last time.”   Sadly this is true for all and we lost Kevin all too soon.

I am going to miss Kevin.  I spent a lot of time on his website reading and commenting , If you go there you will most always see a comment from me or Daniel in the comment section of nearly every post.  Indeed is commenters are often subject experts   themselves and were always well behaved and spoken,  It was like the barbershop for firearms and military vets and firearms historians to go hang out at instead of working on their own stuff.

We hope Kevin has found peace, and we offer our condolences to Kevin’s Brother and Father and offer whatever assistance we can give if we can some how help ease their grief,.

Below is the post from his brother and a link.  If his brother updates with more info we will try to edit and add it to this post.

Good bye Kevin, we are all diminished.

www.weaponsman.com

 

Kevin O’Brien

I’m sorry to have to tell you all that my brother Kevin O’Brien, host of this blog, passed away peacefully this morning at Brigham and Women’s Hospital in Boston.

Let me start with some housekeeping.  First, the email address [email protected] remains active and you may get more and better updates there.  I say this because frankly I’m having trouble posting here.  I don’t know Kevin’s WordPress password and I’m afraid that if I restart his computer, I will not be able to post any more because the password will not autofill.  Therefore I can’t guarantee I will be able to make more updates on the blog.

We are planning a celebration of Kevin’s life for all of his friends some time in early to mid-June, here in Seacoast NH.  I will have details in a couple of days.  All those who knew and loved Kevin, including all Weaponsman readers, are welcome, but we will need an RSVP.  Again, I will make details available to those who write to [email protected]  This is not restricted to personal friends of Kevin, but space will be limited, and we will not be able to fit everyone.  It will be a great opportunity to share memories of Kevin.

We will be looking for stories and pictures of Kevin!  Please send to the email address.

I expect that some time after the celebration, I will be shutting down the blog.  No one other than Kevin could do it justice.

Finally, you should know that Small Dog, whose real name is Zac, has found a home with other relatives of ours.  Of course the poor guy has no idea what has happened to his beloved friend but his life will go on.

Now I’d like to tell you more about Kevin and how he lived and died.  He was born in 1958 to Robert and Barbara O’Brien.  We grew up in Westborough, Mass.  Kevin graduated from high school in 1975 and joined the Army in (I believe) 1979.  He learned Czech at DLI and became a Ranger and a member of Special Forces.

Kevin’s happiest times were in the Army.  He loved the service and was deeply committed to it.  We were so proud when he earned the Green Beret.  He was active duty for eight years and then stayed in the Reserves and National Guard for many years, including a deployment to Afghanistan in 2003.  He told me after that that Afghan tour was when he felt he had made his strongest contribution to the world.

Kevin worked for a number of companies after leaving active duty.  He had always loved weapons, history, the military, and writing, and saw a chance to combine all of his interests by creating Weaponsman.com.  I think the quality of the writing was what always brought people back.  Honestly, for what it’s worth, I have no interest in firearms.  Don’t love them, don’t hate them, just not interested.  But Kevin’s knowledge and writing skill made them fascinating for me.

Kevin and I really became close friends after our childhood.  We saw each other just about every day after he moved to a house just two miles away from mine.  In the winter of 2015, we began building our airplane together.  You could not ask for a better building partner.

Last Thursday night was our last “normal” night working on the airplane.  I could not join him Friday night, but on Saturday morning I got a call from the Portsmouth Regional Hospital.  He had called 911 on Friday afternoon and was taken to the ER with what turned out to be a massive heart attack.  Evidently he was conscious when he was brought in, but his heart stopped and he was revived after 60 minutes of CPR.  He never reawakened.

On Saturday, he was transported to Brigham and Women’s where the medical staff made absolutely heroic efforts to save his life.  Our dad came up on Sunday and we visited him Sunday, Monday, and today.  Each day his condition became worse.

As of last night, it was obvious to everyone that he had almost no chance of survival; and that if he did by some chance survive, he would have no quality of life.  Kevin’s heart was damaged beyond repair, his kidneys were not functioning, he had not regained consciousness, and he had internal bleeding that could not be stopped.  We made the decision this morning to terminate life support.

I’m not crying tonight.  I got that out on Saturday.  What I feel is a permanent alteration and a loss that I know can never be healed.  I loved Kevin so much.  He was brilliant, funny, helpful, kind, caring, and remarkably talented.

At dinner tonight, we agreed that there are probably many people who never “got” Kevin, but there could not be anyone who disliked him.  Rest in Peace.

Please feel free to express your thoughts in the comments and to the [email protected] email address