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Posted: 5/24/2025 8:42:10 AM EDT
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I have some barrels with adjustable gas blocks and I’m trying to figure out which buffers I should use? I would think the lightest possible tuned down would be best, but my buddy who is pretty smart thinks the heavier the better. Will tune to have ejection in a 3-4 o’clock ejection pattern. Thoughts? |
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I found that running a 20" upper combined with a standard rifle length tube and a Kynshot hydraulic buffer slowed my ROF from +/- 750 RPM to just over 600 RPM. Buffer effect on rounds per minute Raymond |
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Originally Posted By kingoftheriver: I found that running a 20" upper combined with a standard rifle length tube and a Kynshot hydraulic buffer slowed my ROF from +/- 750 RPM to just over 600 RPM. Buffer effect on rounds per minute Raymond I used to use an MGI, if they are even available now but I switched to Kynshot; I run a light setup that I all but copied from Amphibian that doesn't bottom at the end of the buffer tube. I don't think anyone knows more about this than Amphibian; perhaps he will chime in. ETA: I guess Amphibian does use the Surefire OBC; it really is exceptional...and priced that way. |
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i follow amphibians posts and really respect what he has done. Wish I had the tools, and more importantly the skillset that he has. I run the 20" upper and the old school fixed stock because I like the old school look and handling of a rifle rather than a carbine. I suspect you will find the hydraulic buffer to be most consequential part of your quest. Raymond |
| With a properly tuned adjustable gas block, the lightest possible reciprocating mass will give the least sight picture disruption and thus be perceived as “smoothest”. Competitive 3-Gunners have known this for decades. However, the tradeoff is that the rifle becomes less reliable in adverse conditions (e.g. after firing a lot of rounds without cleaning/lube). |
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20+ years ago.....before Kynshot existed or the Enidine.... Colt had contracted another company to make hydraulic buffers which were used in the Colt LMG as well as one made for 9mm. I never had the LMG hydraulic but I did have one of the Colt carbine hydraulics. Here is an old picture of one I had purchased from Dennis Todd at Knob Creek. It busted during a match and leaked all over the place.  I later tried the Enidine and never liked them. Kynshot came out with basically a clone of the Endine with the same weight and spring weight and didn't like it either. It wasn't until they came out with the RB5007 which I liked and is my goto still to this day. Before then, I did use the MGI buffer's as well as the AAC pictured above as those worked great for the 7.62x39 setups which require a lot of force to strip rounds off the rough combloc AK mags / drums w/ my MGI lower. Today, I like to run 'extended' stroke setups for 556 as documented on my site here: https://c3junkie.com/?page_id=1403 The key here is not just proper port sizing, but also a large volume gas tube to increase the dwell time instead of just throwing mass at the problem. If you watch closely at the high speed video notice that upon the initial recoil impulse the mass of the RB5007 moves forward to help mitigate the recoil. My camera is doing 1000FPS and I think an even faster camera would catch this even better. As discussed at my site, I don't want the buffer to bottom out in the buffer tube at all. I just want to have that initial forward movement and then also stop bolt bounce when chambering the round so that you don't have light hits in full auto. The RB5007 does this perfectly. Here is another video in normal speed, this was clocked at 561 RPM.  The Ultimate M16 by Amphibian! (The ROF is mint). Below is my favorite setup using a 11.5 Mid with a custom large volume gas tube that I TIG welded.  Bel |
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In military rifles, buffer weight gets adapted to barrel weight, specifically for full-auto reasons. And they could spec out any port size they want, instead of, or in addition to, speccing out a different buffer. The regular M4 had an H1 (instead of H0, for more reasons than barrel weight), and the M4A1 uses a H2. The Mk18 has had a variety of buffers, and a general trend seems to be that the heavier barrel versions get matched with heavier buffers, on average. Lighter buffers have less sight movement, if gas drive is accordingly set up. |
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