AR 15 buffer question

Discussion in 'Rifle' started by boostless, Apr 7, 2017.

  1. boostless Active Member

    Member Since:
    May 5, 2014
    Message Count:
    201
    I am upgrading my 9mm buffer to a correct length and heavier buffer with an upgraded spring. I did my research on that but I'm wondering if I can use the old 9mm buffer in my 5.56 or 6.8spc rifle. The buffer length is correct but it's made of steel not aluminum. My thought on this is that they used aluminum so that the buffer would deform and not the BCG upon the impact through the cycle of the fire arm. I was doing some research and found that they make stainless steel buffers, but same concept applies(I think). The softer metal of the stainless will deform before the bolt will.

    Anyone have any insight or experience with this? FYI my new 9mm bolt is stainless.

    This is the original buffer:
    http://palmettostatearmory.com/9mm-steel-body-buffer-assy.html

    This is the buffer I'm upgrading to:
    http://www.joeboboutfitters.com/KVP...back_Buffer_7_5oz_p/kvp-buffer-7.5-9mm-ss.htm
  2. boostless Active Member

    Member Since:
    May 5, 2014
    Message Count:
    201
    The reason I want to use the old buffer in my other rifles is that is approximately the same weight as the H3 buffers.

    **Edit post wouldn't load correctly?
  3. boostless Active Member

    Member Since:
    May 5, 2014
    Message Count:
    201
    Doing a little more research, there have been people to run the 9mm buffer in other calibers. Only thing that I have seen is that when there is no weights inside the buffer you end up getting "bolt bounce." That bounce supposedly only comes into play when running in full auto, which I don't intend on doing so I should be good.

    *****This is with the standard length 9mm buffers, not the extended 9mm buffers where no spacers are used.
  4. spamassassin Well-Known Member

    Member Since:
    Aug 8, 2014
    Message Count:
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    Higher buffer inertia can cause timing changes to the bolt cycling resulting in slower opening. Since most AR barrels are overported on the gas port, thus they're overgassed, that's not really so much a problem as it might just be a solution to overstressing of brass by early opening common to short barrel AR's (14" and under are especially bad). However, if you're not overgassed (which is very difficult to tell without high speed video) then you might just find you get FTE's and FTF's and depending on your fire control group (if it's anything like mine) the gun might just run FA on you (mine did when I induced a similar condition with bad powder selection). I would recommend a titanium firing pin as a precaution. The increased forward momentum might get you a slam fire with a NATO weight firing pin. Bolt bounce isn't just a problem for feeding. It may lead in really edge cases to an out of battery discharge which would be catastrophic to the upper and lower and the arms holding them.
  5. spamassassin Well-Known Member

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    Aug 8, 2014
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    I'd call up PSA and ask. They're usually pretty helpful.
  6. boostless Active Member

    Member Since:
    May 5, 2014
    Message Count:
    201
    Well I got the 7.5 oz 9mm buffer and spring in yesterday and installed it. The PSA buffer that came out does in fact have something rattling around inside there so if the new buffer works out I'll strip it down and see what's going on inside there. I also picked up a H1 buffer when I ordered some more AR9 mags so I'll step it up slowly and see how it goes for the 556/68 rifles. I'm looking to get a slightly less recoil so my wife will be more comfortable with shooting them. She has seen the "fail" videos of people shooting rifles that they shouldn't have been.

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