AR Buffer Weight Question

[camoman33935]

Hey yall,

So earlier I was looking on BCM's website and saw the different weight buffers available. They were H, H2, and H3 I believe. My question is what is the benefit of using a heavier buffer? I have a DPMS 16" A2 carbine upper and a standard weight buffer right now just for reference but I'm hoping to switch over to a BCM 16" M4 profile upper in the near future.

Thanks yall.

 

[Bartholomew Roberts]

The purpose of the heavier buffer is to slow the time it takes for the bolt to unlock so that the brass has more time to shrink away from the walls of the chamber in order to increase reliability (up to a certain point). However, if you add too much weight for the load you are shooting, you may cause the rifle to short stroke or not function at all.

Some people also like the heavier buffers because it changes the subjective feel of the recoil (spreading out the same force over slightly more time). Others like lighter buffers because the less mass moving around, the less the sight picture is disrupted between shots.

Really, you can tweak the buffer weight to suit whatever your personal goals of smooth recoil/reliability are. The military issue M4 uses an H-buffer as issued.

 

[d2wing]

My rifle has more reliable extraction with an H2 buffer. Some opinions are that a heavier buffer will improve extractor and bolt reliablity for the reasons above poster stated. It slows down the rate of cycle and absorbs more of the energy of the shorter carbine action as well as giving the case more time to contract for easier extraction. It depends mostly on if your rifle is overgassed or has extractor issues. Some go lighter for faster sight recovery or because of shortstroking as already stated.

 

[Kwanger]

I only really started messing with buffer weights etc when I got into 3 gunning and needed quick follow up shots. I had never thought about even a carbine gas AR having a supposed harsh recoil before....however, when I added a compensator instead of flash hider, I could really feel it. Switched out my standard carbine buffer for a Spikes ST-T2 (near H2 weight), and the standard spring for a Sprinco heavy duty (red), and the difference is really noticable in the felt/perceived smoothness of the rifle.
YMMV rifle to rifle and ammo to ammo however....if you do start messing, be prepared to test several options.

 

[W.E.G.]

Your body movement at the time the shot is fired can be the difference between function and malfunction.

If all you ever do is brace your gut against the bench, and lie on top of the gun, you may never experience such a malfunction. For a "working gun," brisk cycling might give you a little extra margin for reliability.

Don't "over-buffer" the gun if you might ever shoot it not on the bench.

 

[Z-Michigan]

Don't "over-buffer" the gun if you might ever shoot it not on the bench.

Or just practice with it under a wide range of realistic scenarios. I'm running an H2 in an M4 style gun, everything is working great and it's run through two 2-gun matches and some practice without a hiccup. YMMV! I agree with all who are saying to test everything thoroughly and with different combinations once you start playing with buffer weights.

 

[Tirod]

There is another benefit of heavier buffer weights, and that is at the other end of the cycle. Vuurwapen's blog has high speed video of light and heavy buffers in action, same gun. One of the more pronounced affects of buffer weight is the elimination of bolt bounce, especially in carbine length actions. You can actually see the bolt reopening a partial amount. If the timing of the shot was just exactly wrong, the bolt would be unlocked just as ignition set in.

Midlength and rifle gas don't seem to have the number of kabooms that carbine does, but it could be a simple matter of numbers, reject ammo, and the kind of shooting M4gery owners indulge in. It's rare enough. What is known is that the light buffers aren't optimum, and few shooters can articulate a good reason for them other than "It's not broke, don't fix it." Those that do change largely mention reduced recoil and the potential benefit of reduced wear, stoppages, and parts replacement. They do shoot multiple "combat tours" of ammo over years on the range, compared to a soldiers single tour. That extensive long term use seems to bear out going to a heavier weight.

 

[killchain]

Your body movement at the time the shot is fired can be the difference between function and malfunction.

If all you ever do is brace your gut against the bench, and lie on top of the gun, you may never experience such a malfunction. For a "working gun," brisk cycling might give you a little extra margin for reliability.

Don't "over-buffer" the gun if you might ever shoot it not on the bench.

Come on now, no one here shoots from the bench.

In all honesty, I use an M4 for work and play and I have never shot it from a bench, and this is the first I have ever heard of buffer weights. I kind of attribute it to certain car parts... did you know you needed them until someone told you you needed them?