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.

20 thoughts on “5 Reasons for the AK’s Legendary Reliability”

  1. Thanks for posting Shawn.
    Such a pitty we can’t get Kevin’s opinion on the US military’s current noise about a new 7.62 rifle.

    1. There have been a mountain of things that have developed since his passing about which I wish we could read his ruminations on. He is sure to be missed the rest of my life.

  2. I wonder what Hognose would have had to say about the AK50 that’s being developed. I’m sure that that write up would have been a good one.

  3. One additional reason has to do with the ammunition.

    NB the taper on the case of the 7.62×39 round. It has a steeper-than-average taper, if you compare it to western cartridges. Look at cartridge drawings of the 7.62×39 vs. the 5.56×45 or 7.62×51. The American/NATO cartridges have less taper over the length of the case body between the shoulder just forward of the extraction groove and the rear edge of the shoulder.

    This makes extraction much easier and a lower-force proposition. If you want to see other examples of “high-taper” cartridges to aid in extraction, look at the cases used on dangerous game double-rifles – ie, the side-by-side rifles with very little extraction force.

    Most people fail to appreciate just how much extraction force a bolt action rifle is able to generate – it’s pretty significant. The force that a bolt rifle can generate to push a cartridge into the chamber is even greater. A semi-auto has nowhere near this amount of force available – the case better be able to get in there and get back out pretty easily, just as cartridges made for the old double rifles had to be more heavily tapered to allow reliable extraction in an action with low extraction forces.

    The 5.45×39 also has more taper than the 5.56 NATO.

    The 7.62×51 case has even less taper than the 5.56 NATO.

    If I were designing a cartridge that absolutely, positively, had to extract every time – I’d be taking my cue from the old African dangerous game rifles, just the way the Russians did on the 7.62×39.

    1. since the early 90s I have wished US makers had made a bolt action target rifle in 220 russian.

      You know man, you always have so much stuff to say worth reading . If you were inclined and wanted, this website is open to you for your own posting. We can give you an account or I can post it for you as “guest” I’d be proud to have you on.

      That offer is extended to several of Kevin’s readers/commenters who we all know who they are. All you have to do is tell me.

      1. Well, there were makers of bolt-action rifles in cartridges based on the .220 Russian. They just didn’t advertise in glossy gun rags. Well, maybe. Sako put out a rifle in .220 Russian.

        The .220 Russian is the parent brass for the 6mm PPC cartridge, which has ruled the benchrest world for a long, long time – since the late 70’s. The canonical pill for loading this case is now the 105gr VLD or similar bullet. Shootists who load the 6 PPC typically use .220 Russian Lapua brass as their parent brass. Benchrest ‘smiths have been building rifles for this cartridge for decades now – usually based on a Rem700 short action, or a compatible action. You just weren’t able to get such a rifle from a mass production company. The history of the 6 PPC cartridge is very interesting – a collaboration between a gunsmith and a dentist. The same sort of collaboration led to the .408 CheyTac. When I meet a dentist on a shooting range, I tend to stop and listen to him. I dunno why it is, but I’ve never met a dentist who was a shooter from whom I didn’t learn something.

        If you’d like, sure, give me a login. I’ll comment where possible and constructive. I’ve never served, so my perspective on guns is that of an engineer turned gunsmith – which is to say, I’m not someone who absolutely had to have his weapon go “bang” instead of “click” at inopportune moments. This is where I will miss Kevin’s experience and expertise greatly.

        As Yogi Berra once quipped: “The difference between theory and reality is that in theory, there is no difference.” Engineers often dwell in the domain of theory; unit armorers (I’m sure) have nowhere to go but the Land of Reality.

        1. Yea brother I know all about the 220 russian and the 6mmPPC. I started my precision shooting and reloading career under the mentorship of the NNBRSA/IBS. I was turning 220 russian cases and 7.62×39 cases into 6PP cases before some of this website’s readers knew you could handload I’m sure.

          Military service is not a requirement to post here. I never did either. Howard is the only Vet that writes here. If you want to do pure technical ruminations. that would be swell. Give me an email and we will talk about it.

      2. Shawn, if you could get DG posting regularly, that would be awesome. Other blogs have tried. My suggestion: Feed him article ideas regularly. 🙂

        -John M.

        1. Probably can’t bride genius ! I would love to but I think he isnt interested

          That offer extends to you too ya know. If you want to guest post you are more than welcome to. I would publish any of Kevin’s more regular commenters article ideas or reviews etc , with complete confidence. email me if you want to give it at try.

          1. I’m humbled by the offer, Shawn. I considered myself among the buck privates of Weaponsman.com. I had so much to learn from Kevin. (I mean seriously, how many people know off the top of their head that the FN-FAL had firing pin issues, never mind how they got solved?) And I still have much to learn from the other regular posters. With that said, you might just get an email from me one of these days. 🙂

            -John M.

    2. DG,

      It seems like the main disadvantage to a highly-tapered case is loss of powder capacity in the case relative to length of the case and diameter of the case. Are there other downsides to a highly-tapered case like 7.62×39?

      -John M.

      1. Yea in some cases it has some downsides but they are mostly things that concern BR match shooters. As you said, slightly less case capacity. Also reloading them of course works the brass more and leads to faster work hardening, Also slightly less case life. And some argue that the internals of a tapered case aren’t as conducive for meeting its full accuracy potential as a more straight lined case is. Thats part of the “Improving” of the type done in the Ackley line and others like them. There are a few other real or imagined, arguments for or against in dubious and varying degrees.

  4. A repeat for me but a worthy one.The old adage”Keep it simple stupid” really had the AK in mind.Thanks for post and look forward to meeting folks that can make it this Sunday in the celebration of Kevins life,offer for ride from Manchester airport or a ride in N.H. still open you need it.

    1. I guess I should have mentioned here. I won’t be making it to the event for Kevin, My own Mother is having heart surgery the following Monday and its been planned since before Kevin passed away.

      For you guys being there please pass on my regret at not being able to come in person.

      1. Shawn,will do,family always comes first,something Hognose would also say.Best of luck with your mum and a quick/healthy recovery.

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