Does AK reliability really come from "loose tolerances" ?

Discussion in 'Rifle Discussion' started by raftman, Mar 28, 2015.

  1. raftman

    raftman
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    Loose tolerances is a term that gets thrown around quite often when it comes to guns and to me it's become about as annoying as using "clips" and "magazines" interchangeably. For example, the AK's reliability is often attributed to "loose tolerances" but (and I could be mistaken) this isn't really the case. When someone mentions loose tolerances in this context, they usually mean that all of the critical parts are spaced and positioned in such a way as to make it less likely that any sort of fouling would impede function. This is an example of loose clearances, not loose tolerances.

    To make an analogy, a higher bridge allows taller vehicles through because its clearance is greater, not because its individual components are made to less-exacting specifications than shorter bridges (it could still very well be made to less-exacting specs, but this will have little to do with what can pass underneath). So it is with the AK; for example you can go thousands upon thousands of rounds without cleaning the gas tube not because of the small difference in dimensions from one gas tube to the next, but because the gas tube's design allows for it regardless of such differences.

    No doubt your typical AK is indeed made to less-exacting specifications than some sort of high-end competition rifle. However, the fact that it doesn't need to be made extremely precisely in order to function as intended only goes back to the loose clearances of design, rather than the tolerances to which it is manufactured.

    I'm curious, if I'm completely wrong about this or....?
     
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  2. IronMonster

    IronMonster
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    I think you are correct. I think it's a case like you say of poor nomenclature.


    It can be crude, rough and somewhat miss machined or alined and still function flawlessly, however all the parts must be within tolerance however broad that -/+ range is. It's the loose interplay of parts, however you want to define it.


    That is not to say that precision things are inherently unreliable. That is typically the inverse of what's true however small amounts of unintended grit can wreck havoc on something that is insanely reliable in other circumstances.


    How about we just say AK's work well because of the built in mechanical redundancy brought about by the lack of friction atrubutes and excessive clearance of interacting assemblies?
     
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  3. Joe13

    Joe13
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    Ain't it passible that yur just being a little sensitive about something that only probably 10% of this group will comprehend much less understand?

    So if a clip feeds a magazine, does that make my wallet a clip???:rolleyes:
     
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  4. raftman

    raftman
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    Oh I know it's nitpicky... but I suppose it's one of those things that people say that reveals they don't know very much about what they're talking about.
     
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  5. Joe13

    Joe13
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    Touché
     
  6. Gator Monroe

    Gator Monroe
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    Milled Type 2 FA AK is not a loose as you guys make it seem .
     
  7. Stomper

    Stomper
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    o_O... :rolleyes:
     
  8. ron

    ron
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    I agree. Reliable yes. Not as accurate? My experience is yes. What size of group do
    you get at 200 or 300 yards? It is a good rifle for throwing lead but past 200 yards
    not so much. IMHO
     
  9. Jamie6.5

    Jamie6.5
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    Without the original machining/stamping/clearance specifications from Kalashnikov, we have no way to know whether it is a matter of loose "tolerances" or loose "clearances."
    But the fact that manufacturing one starts with a stamping, as opposed to the machining of a billet, or a forging should be the first clue.
    Stampings will never be as precise as a finish-machined billet. That's just not possible.
    The semantics of users on the fringe of understanding of machining and manufacturing processes aside, Kalashnikov engineered and prototyped a weapon intended to be functional under the most adverse of conditions, and with minimal maintenance.
    But he managed to come up with a design and execution that was intended to do those things on the cheap. IOW, "cheap" from a materials standpoint, and "cheap" from a manufacturing-labor standpoint, and "cheap" from a quality control standpoint.
    That means workers/assemblers with minimal training and critical judgement as to the product they built. Which was the Soviet model for much of what they did in the way of manufacturing, and even buildings and structures.
    Ever see soviet era buildings like apartment-multi-family housing? It was all very spartan and simple, and even though most of it had at least one aspect that was falling apart as soon as it was completed, it served to house people. Most had at least one structure, feature or function that never worked right. From staircase handrails to hot water heaters, to door locks and even foundation integrity, but the residents survived cold winters and managed to survive,, if not thrive.

    So, were AK clearances "loose" by design and specification, yet required a high degree of precision in the machining/stamping/fitting processes?
    I doubt it.
    Starting with a stamping as the framework to establish the reference point(s) for the stationary and moving parts, and welding in the anchor points, it's fairly clear that the ability to hold tight clearances goes out the window. That indicates a design that "tolerates" loose tolerances while retaining functionality.
    That fact, in and of itself indicates that "loose tolerances" were the order of the day.
    If that philosophy is carried through the process(es) of building one start to finish though, it becomes a matter of fitting other parts, built/finished to the the same broad range of tolerances to the machine to facilitate acceptable function.

    When we assemble something like an AK, chances are we have a parts kit or two from which to choose parts that fit, and must massage them, or hold location/fit tolerances to suit ALL of the parts. And they were manufactured with that in mind. I doubt the soviets did that.
    Soviet factory fitters didn't work under those restrictions. They had bins full of parts that probably numbered in the thousands. If the first one didn't fit, they grabbed the next one until they found one that did.

    Loose tolerances were the order of the day. But the genius of the design, is that it's still a functional and lethal weapon when manufactured under those conditions, by those workers, using those tolerances.
     
    Last edited: Mar 29, 2015
  10. Greenbug

    Greenbug
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    So is it the AK's tolerance for loose clearance that makes it reliable, or is it that AK's have clearance for loose tolerances?:confused::confused:
     
  11. ogre

    ogre
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    Nice post Jamie.
     
  12. The Heretic

    The Heretic
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    Partly. I don't disagree that those contribute, but they are not the only reasons.

    When I think of the "reliability" of an AK I think of the following:

    a) The mass of the gas piston and the bolt carrier, along with the recoil spring.

    b) The fact that the bolt carrier rides on rails. Unlike the AR and some other rifles where the bolt carrier rides more or less within a tube. The difference in the bearing surface and the friction, especially when there is debris in the action, is significant. The rails in the AK action have a MUCH smaller surface area, and tend to be self cleaning.

    c) The "loose tolerances".

    d) The magazine, especially the magazine lips. As most knowledgeable firearms people know, in most "box" magazine fed firearms, the magazine is the heart of the action and the feed lips are the most crucial part of the mag. If the lips are deformed, this greatly increases the chances of misfeeds.

    AK mag lips:

    MagFeedLips.jpg

    AR mag lips:

    Broken-Magazine-1.jpg

    When you first look at the AK mag, it almost looks like the mage lips are machined from billet steel they are so robust and thick. Conversely, the AR mags are obviously just pressed steel or aluminum (depending on the mag).
     
  13. Gator Monroe

    Gator Monroe
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    Seems many of you like to compare the Tolerances of a:eek: 2004 Romanian WASR 10 Century Arms Import AKM to a 1958 Type 2 "Milled" receiver Russian AK o_O
     
  14. Stomper

    Stomper
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    The AK started out with a machined receiver and stamped dust cover, the AKM came out a while latter (1959) with a stamped lower, spot welded rails, pressed in and riveted trunions/barrel. Supposedly the AMK is more accurate in full-auto than the AK, but I wouldn't know as I've only fired AKM's.

    "Tolerances", "clearances", it's simply a robust design with strong springs, and a configuration that shucks enough dirt/build-up out of the critical "doin's", with enough room inside that it takes a LONG time to get packed up enough to bog down.

    Those clearances fall within the design tolerances, yes?


    I have a nicely built (believe it or not) WASR-10/63 that would SERIOUSLY suprise you with how accurate it shoots.
     
  15. Gator Monroe

    Gator Monroe
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    Comparing a "Milled" Hungarian or Russian or even Chinese Norinco/ Poly or Legend to any Stamped AKM is not fair analysis
     
  16. Sam Kinard

    Sam Kinard Active Member

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    There is no doubt that milled AK's compared to stamped is the proverbial apples & oranges.

    I have owned many of each and I firmly believe that the Norinco MAK-90 and the Polytech Chinese AK's are without a doubt the best available to the American population. It should also be noted that the Chinese guns use a thicker barrel, which is more conducive to accuracy as it heats up.

    I use Bulgarian AK74's and Saiga's. I love the quality of the milled Saiga's, but I have one particular Bulgarian on a Nodak Spud that is amazingly accurate.

    Glocks vs. 1911, AK vs. AR, AK vs. AK. If we ever resolved these arguments, what would we talk about?
     
  17. oli700

    oli700
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    9mm vs 45acp ?
     
  18. The Heretic

    The Heretic
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    The design is more or less that same.

    I have owned Chinese AKs that varied from decent to slapped together so they could import them before the ban went into effect - they all worked (although some towards the end needed some file work to take off the sharp edges so they wouldn't cut you or so a mag would fit).

    I've also owned Valmets, which along with a Galil are the Rolls Royce of AKs.

    While there are differences in manufacture, the design was the same more or less and with one exception they were all reliable.

    The one exception is the CIA Galil clone and I think the problem with that is that they were sloppy with the gas port and it ejects too energetically ripping part of the rim off the shell - either that or the chamber tolerance is too tight. Either way, bad quality control on the part of Century Int. - trust them to be the one supplier who can screw up an AK. :rolleyes:

    So I don't buy the difference between "milled" and "stamped" - I have owned both and both worked fine over a long period of time and in various conditions including mud and sand. They both have the same design and features. And it isn't just me - millions of people worldwide use both milled and stamped AKs with good results.

    US firearms owners may have their preferences, but I think overall there isn't a whole lot of difference when it comes down to whether they milled the receiver or stamped it with regards to reliability out of the box. The milled receivers will probably last longer, especially in rough usage - but that is durability, which is somewhat different from reliability.
     
  19. The Heretic

    The Heretic
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    I have both, and what I will use will depend on what ammo is available - most likely 9MM.
     
  20. oli700

    oli700
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    aimpoint vs eotech ?
     

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