Is the 5.56/.223 more to blame?

Discussion in 'AR-15 Discussion' started by CamoToe1, Dec 1, 2013.

  1. CamoToe1

    CamoToe1 New Member

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    I still haven't experienced a stuck case in my AR. I've been thinking about the shape of the case as compared to the 7.62 x 39. If you compare the two there's an obvious difference in taper. This leads to the banana looking AK mag vs the straighter AR mag. Also, the chamber contact area seems smaller(haven't actually measured this). Common sense would tell me that the 7.62 x39 would lend to easier extraction due to more taper and less surface area in contact with the chamber.

    AR15's are extremely reliable In their current form. Should the 5.56/.223 round itself be blamed for some of the earlier reliability issues?
     

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    Last edited: Dec 1, 2013
  2. texaswoodworker

    texaswoodworker New Member

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    IIRC, it was because the barrel and chamber were not chrome lined back then (not a good thing if you are in a humid place like Vietnam), and ball powder (dirty) was used in the ammo vs the log powders (less dirty) we use today.

    So in a way, it was partially the ammo's fault, but not for the reasons you asked about.

    http://www.bobcat.ws/rifle.htm

     
    Last edited: Dec 1, 2013

  3. CamoToe1

    CamoToe1 New Member

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    I'm sure there were many factors early on, such as:
    1. Rough chambers(non chrome lined)
    2. Incorrect powder
    3. Lack of cleaning kit issued
    4. Improper training
    5. No lube or insufficient lube

    But all things equal:

    Do you think the case design leads to a more difficult round to extract?

    Does anyone have a 7.62 x 39 upper?

    Any extraction issues?
     
  4. texaswoodworker

    texaswoodworker New Member

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    No, I don't. The fact that ARs are so reliable today is proof of that. It might just a little harder to extract, but not enough to matter. Definitely not enough to say that's what caused the reliability issues in Vietnam.
     
  5. trip286

    trip286 New Member

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    I think you're onto something. It does seem to me that the design of the 7.62 round would be an easier one to extract.
     
  6. MisterMcCool

    MisterMcCool Well-Known Member Supporter

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    Didn't Vietnam era 5.56 ammunition use stick powder?
     
  7. CamoToe1

    CamoToe1 New Member

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    Completely agree that it wasn't the only reason, but haven't ruled it out as a minor contributing factor.

    Consider the steel case vs brass case issues we see on here from time to time. AK's seem to run steel pretty easily, however some AR's can be picky eaters. I know.... looser chambers and overgassed piston systems can be cited... But what about the design of the case itself?

    Has anyone on here ran an 7.62 x 39 DI AR upper with a large sample size of steel cased ammo?
     
  8. texaswoodworker

    texaswoodworker New Member

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    They were supposed to. Ball powder was cheaper though, so some dumbass politicians decided to use it instead. A lot of American soldiers died as a result.

    Once they figured out they effed up, they went back to stick powders like they should have done from the beginning.
     
  9. JonM

    JonM Moderator

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    only for a short bit and intermittantly

    case design leads to easier extraction but only so much. long as it has some taper which the 556/223 has thats enough. so there isnt any real diff tween the two in that respect. what makes the ak easier to extract is its extremely overgassed and ripping the cartridge out by brute force and the chambers are larger than they need to be

    they used a poor form of ball powder. as it turns out ball powder burns better under all conditions than stick does. it also burns better in a semi auto.
     
  10. Sniper03

    Sniper03 Supporting Member Supporter

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    Yes all the above reasons were the answer to issues in the past. I have never had a failure to extract! As of late the only significant issues I have seen with extraction and feed have been due to shooting cheap ammunition with the laquer coating which builds up in the barrel over a short period of time. A good simple chemical for furniture stripping will clean it out the best.

    03
     
    Last edited: Dec 1, 2013
  11. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

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    The shape of the 7.62 X 39 is a design feature to make steel cases work properly. The pronounced taper causes the stiffer steel to expand and seal off the chamber. It does not cause problems with brass.

    Ball propellants burn cooler than IMR (stick) powders. In a full auto, heat is built up quickly. Ball propellants (of the 60's) left more residue than IMR powders. This has been addressed with modern formulations.

    The M-16 was a new platform that was not very well understood in the early 60's. Our understanding today has led to better maintenance, better powders, better lubricants and better reliability
     
  12. primer1

    primer1 Well-Known Member Supporter

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    The mosin uses a tapered cartridge, and it never has issues :)
     
  13. therewolf

    therewolf New Member

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    Soldiers were told the M16 "didn't require cleaning in the field".

    Combine that with the poorly manufactured chambers, and bad

    powder previously mentioned, and that is the initial "reliability"

    issue in a nutshell.

    There are reams and reams of mind-numbingly boring information

    concerning these Vietnam-era jams. PRAY you have one of these

    original rifles, they are worth @5K to 10K, if and when you can

    find them, as the DOD went out of their way to scrap them when

    the M16A1A was produced to replace the original M16.


    In practical terms, today, I have a Colt AR in 5.56, do minimal

    maintenance and average to so-so cleaning and lube,

    and have never had a FTF or FTE.

    Want to see a world class jam with a 7.62X.39(M43)?

    Load a new AKM without cleaning the cosmoline out of the

    action and chamber...
     
    Last edited: Dec 2, 2013