AR Carbine Buffer questions

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  • slsc98

    Ultimate Member
    May 24, 2012
    6,746
    Escaped MD-stan to WNC Smokies
    So, I did a search for and skimmed and scanned threads with “buffer” in the title* but, still have some questions as I apparently now have yet another upper (also w mid-length system) that appears to possibly be over-gassed and I remember it being suggested to try a heavier buffer.

    I should start by affirming: Headspace in the upper in question checks out okay …

    The lower is a new PSA and I am ASSuming the buffer in it is milspec so I guess my first question is

    Q-1: What is the weight of a “milspec” buffer?

    Q-2: Is that milspec designated by an “H,” an “H-1” or an “H-2” ?

    Q-3: what is a good source for reliable buffers of different weights?

    Q-4: is this a safe (“good”) bet, to start with, in an attempt to see if the brass gouging goes away? https://www.midwayusa.com/product/1018146330?pid=711733

    A bit of my confusion stems from fact that, in this index, the term “heavy” is applied to not only H3 but also H2 and iirc even H1 buffers:
    https://www.midwayusa.com/s?searchT...&Availability=Available&Compatible+Make=AR-15


    Thanks in advance, the upper in question is proving quite accurate w factory 62 and 64 grain rounds so, I am hoping a tad heavier buffer will resolve the brass gouging (weird as I’ve gone 4 decades now with no uppers ever gouging the base of cases and now I’ve had two different uppers do it in as many months. :sad20:

    *=

    Recommend a buffer spring for overgassed … (SBR, not std carbine): https://www.mdshooters.com/showthread.php?t=260385&highlight=Buffer

    AR pistol buffer tube / Brace:
    https://www.mdshooters.com/showthread.php?t=260567&highlight=Buffer
     

    slsc98

    Ultimate Member
    May 24, 2012
    6,746
    Escaped MD-stan to WNC Smokies
    Pics …

    Not thinking ahead, I didn’t take pics of the brass I fired today (in addition to gifting my once-fired cases to the on-duty RO, the range was off the hook busy and I only snagged a couple pieces the couple times the line was made “Safe.” And, all brass wound up well forward of the firing (“1- and 2 o’clock”) in pretty tall dense weeds but, the marks on base of cases today looked identical to these marks on the cases out of the upper last month from Combat Armory (and which CA had me send back to them … no issues with the replacement they sent me and they were very apologetic) …
     

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    outrider58

    Eats Bacon Raw
    MDS Supporter
    Jul 29, 2014
    49,810
    So, I did a search for and skimmed and scanned threads with “buffer” in the title* but, still have some questions as I apparently now have yet another upper (also w mid-length system) that appears to possibly be over-gassed and I remember it being suggested to try a heavier buffer.

    I should start by affirming: Headspace in the upper in question checks out okay …

    The lower is a new PSA and I am ASSuming the buffer in it is milspec so I guess my first question is

    Q-1: What is the weight of a “milspec” buffer?

    Q-2: Is that milspec designated by an “H,” an “H-1” or an “H-2” ?

    Q-3: what is a good source for reliable buffers of different weights?

    Q-4: is this a safe (“good”) bet, to start with, in an attempt to see if the brass gouging goes away? https://www.midwayusa.com/product/1018146330?pid=711733

    A bit of my confusion stems from fact that, in this index, the term “heavy” is applied to not only H3 but also H2 and iirc even H1 buffers:
    https://www.midwayusa.com/s?searchT...&Availability=Available&Compatible+Make=AR-15


    Thanks in advance, the upper in question is proving quite accurate w factory 62 and 64 grain rounds so, I am hoping a tad heavier buffer will resolve the brass gouging (weird as I’ve gone 4 decades now with no uppers ever gouging the base of cases and now I’ve had two different uppers do it in as many months. :sad20:

    *=

    Recommend a buffer spring for overgassed … (SBR, not std carbine): https://www.mdshooters.com/showthread.php?t=260385&highlight=Buffer

    AR pistol buffer tube / Brace:
    https://www.mdshooters.com/showthread.php?t=260567&highlight=Buffer

    1) It varies depending on the gun type/length

    2) See above

    3) You can configure your own using a KAK buffer kit https://www.kakindustry.com/ar-15-parts/lower-parts/buffer-tubes-and-parts/ar15-buffer-system

    4)It's safe but you can also start with springs (see Sprinco) https://www.sprinco.com/

    5) Middies are over gassed because of their shortened dwell time compare to carbine gas length barrels. It gives them better reliability with a wider array ammunition types.

    Chart on buffer weights and configurations(this chart is not complete)
     

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    ken792

    Ultimate Member
    Sep 2, 2011
    4,480
    Fairfax, VA
    The original carbine buffer has three steel weights and weighs 3oz. The H-H3 buffers swap out the steel for tungsten and go up in weight.

    Current military contract M4A1s ship with an H2, but that is with an actual M4 barrel shooting US government contract ammo. What is mil-spec is kind of irrelevant unless your AR also has a government barrel shooting government ammo.

    https://www.ar15.com/forums/ar-15/Military-M4a1-buffer/128-744323/

    I actually buy the cheapest H3 buffers I can get, which is the AR Stoner brand from Midway with birthday pricing at $20 each. That's cheaper than buying three loose tungsten weights. Then, I start swapping around steel and tungsten weights between the cheapo carbine buffer and the H3 buffer until the AR cycles appropriately and runs with the lowest gas impulse ammo I intend to use in the coldest weather I have access to.
     

    calicojack

    American Sporting Rifle
    MDS Supporter
    May 29, 2018
    5,348
    Cuba on the Chesapeake
    In addition to different buffer weights and/or stiffer buffer springs (which Outrider outlined in great detail), an adjustable gas block, or tuned gas tube are also possible solutions. The tuned gas tube can be used if you have a fixed front sight which (AFAIK) has no good adjustable gas option. A VLTOR A5 buffer system is yet another solution; this is a slightly longer buffer tube with it's own buffer and spring which can tame an over-gassed AR.

    The tuned gas tube, made by Black River Tactical, is basically a gas tube that has a different port hole size (I believe) based on whether you want more or less gas. It is fixed; you get one size and run with it. https://blackrivertactical.com/WP/BRT-EZTUNE-Gas-Tube-Configurable-Midlength-p103167236

    I have literally done all of the above; although I have yet to try the VLTOR system (at the range) yet.
     

    slsc98

    Ultimate Member
    May 24, 2012
    6,746
    Escaped MD-stan to WNC Smokies
    Outrider, Ken, calicojack - THANK YOU!

    (Apologies for any lag in replying, I wanted to get outside while the 4”-5” of white stuff we’ve already had fall was still conducive to being moved by a leaf blower; once temps rise just the smidge it takes to go from powdery granules to wet crap, that window closes!)

    Outrider, if “a picture is worth a thousand words,” hehe well, a thousand thanks, sir!

    Ken, you read my mind as the number of msrs now under one roof and my mind was heading toward the ease of keeping on-hand multiple buffers, springs and as Outrider mentions, kits (LOL, I mean, when I can wait for the windows to get PSA lowers for 130, Delton complete uppers for under 300 and LaRue MBT’s for 100 why wouldn’t we have them already / all ready for great grandkids, who aren’t even born yet?

    Calico, as Morgan Wooten of DeMatha always said, “never say never” but, I’m intentionally not going any “tunable” route right now … may change but for now …


    ETA - d*mn, that KAK kit looks like the bee’s knees!
     

    calicojack

    American Sporting Rifle
    MDS Supporter
    May 29, 2018
    5,348
    Cuba on the Chesapeake
    Calico, as Morgan Wooten of DeMatha always said, “never say never” but, I’m intentionally not going any “tunable” route right now … may change but for now …

    The tunable gas tube might be best suited for running a suppressor or, you want to run multiple uppers on the same lower and don't want to change out the buffer and/or spring each time.
     

    omegared24

    Ultimate Member
    Dec 23, 2011
    4,747
    Ijamsville, MD
    I actually buy the cheapest H3 buffers I can get, which is the AR Stoner brand from Midway with birthday pricing at $20 each. That's cheaper than buying three loose tungsten weights. Then, I start swapping around steel and tungsten weights between the cheapo carbine buffer and the H3 buffer until the AR cycles appropriately and runs with the lowest gas impulse ammo I intend to use in the coldest weather I have access to.

    This is certainly the best way to test. I have a little scale to weigh my buffers and keep notes. I've even experimented with lead ball bearings to see what I could come up with.
     

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