AR buffers

[JamieC]

I just did some reading the other day on different weight buffers used in AR15s. Didn't know there were different weights and springs, after reading and educating myself a bit, it makes sense. How much actual benefit is there in tailoring a buffer to a specific gun? My gun isn't suppressed, it's mainly a range gun, SD. From what I read, recoil can be reduced a bit by having the 'correct' buffer/spring set up, true?

 

[Inebriated]

Besides reliability, buffer choice can go a long way in making the gun shoot smoother. Not necessarily reduced recoil, but a smoother impulse.

As long as your rifle functions, you can use whatever buffer you like best. I'd get an H, H2, and H3 buffer and thoroughly test each one with ammo you shoot most. Use the one that feels best to you without hindering reliability.

 

[Welding Rod]

For 16" mid length guns I have never used anything other than a standard carbine buffer, or a rifle buffer if a A1 or A2 stock were used. I have never had a Malf attributable to a buffer.

Same deal with 20" guns. Always use a rifle buffer or a standard carbine buffer for a telescoping stock. Never a Malf attributable to a buffer.

 

[greyling22]

for what it's worth, I've been using a spikes h2 buffer with first a midlength and then a carbine gas system. Never had a malfunction related to a cycling with either. Can't really tell a difference between it and a regular h buffer. H2 came free with my upper, so I run it, but I wouldn't pay extra money for it.

 

[minutemen1776]

I run a Spike's ST-T2 in my LMT lower. It is MUCH smoother than the standard buffer that came with the assembled lower. If I were building another lower, I'd spend the money for a Spike's buffer.

 

[MachIVshooter]

buffer choice can go a long way in making the gun shoot smoother. Not necessarily reduced recoil, but a smoother impulse.

This. In the rifles I've played with them, they all run fine with anything from an H2 to an empty buffer (never used an H3), but without an adjustable gas block, the empty buffer produces a pretty violent recoil impulse. IME, 16" rifles with carbine gas become a lot more pleasant with an H or H2 instead of standard carbine.

Where buffer weight becomes more critical is in a full auto, where too light a buffer can result in bolt bounce, which causes malfunctions. Having said that, we plopped my featherweight upper onto a friend's M-16 lower a couple weeks ago, and it ran fine. The lower had an H2 buffer, but I had lightened my bolt carrier by 2.6 ounces, making the combined weight still lighter than a standard BCG with a empty buffer. No bounce and, if anything, it seemed that the cyclic rate was actually a little slower than any of his uppers. Didn't have a shot timer with us, but it sounded like ~650-700 RPM.

 

[Onmilo]

The standard rifle buffer is 5.2 ounces for 5.56 rifles.
There is no advantage to increasing or decreasing this weight when using a rifle length extension tube.

Carbine buffers come in 3 oz standard, 3.8 oz H, 4.6 oz H2, 5.4 oz H3, and 6.5 oz HSS weights

Pistol caliber and large bore buffers come in weights from 5.6 ounce to 10 ounce weights.

DPMS offers a "Heavy Weight" carbine buffer which duplicates the rifle buffer weight of 5.2 ounces and this is what I use in my 18" barrelled SPR with a sliding carbine stock and extension tube.

The rest of my Carbine stocked AR15s have H buffers in them and the rifle stocked guns have standard 5.2 ounce rifle buffers.

I have had no malfunctions attributed to buffer weight in these weapons.

If you shoot semi auto rifles you will see similar results.
If you shoot suppressed or full auto guns or a combination thereof you may need to tailor a buffer weight for optimum reliability. HTH

 

[lysanderxiii]

Why it makes a difference.

Gas at anywhere from 2500 to 3500 psi enters the bolt carrier for the gas tube and the bolt and carrier act as a piston pushing the bolt carrier and buffer away from the bolt. The lighter the mass the gas pressure has to move the faster it will accelerate, and higher the velocity will be.

The AR was designed to operate with a bolt/carrier velocity of about 10-15fps. Higher bolt/carrier velocities lead to poor extraction, bolt overruns, parts breakage, and other problems. Heavier buffers add to the reciprocating mass and slow things down.

I would only worry about a heavy buffer if you have a problem.

 

[moxie]

Recoil in an AR is negligible to begin with. Any reduction you might achieve by changing the buffer is likely miniscule.

If your AR is already reliable, a different buffer isn't going to improve anything. It might make it worse!

Odds are, if you bought a gun off the shelf, the maker put in the correct buffer.

 

[NWcityguy2]

Shooting an over-gassed AR, it's going to feel jumpy, with excess muzzle movement. The recoil doesn't beat you up (no one is saying that) but the point of aim is moving more than it needs to. That is the benefit to increasing the buffer weight or spring strength. Or reducing the gas, but most of us can't do that with our gas blocks.

I have started using Tubbs springs, which I highly recommend. For any AR that is gassed to shoot cheap steel ammo, throw in a Tubbs flatwire spring and it will be tuned much better for full power 223/5.56 ammo.

https://www.youtube.com/watch?v=8fMVZbrnvu8

 

[carbine85]

My regular shooter is a mid length, FA carrier and H buffer. For me it's a perfect set up. Everyone that shoots it really likes the set up.

 

[cougar1717]

IMHO, there isn't a lot of incentive to change if your rifle is functioning reasonably (brass at least 6' away at 3:00-4:00). Without getting into every case where a different weighted buffer might be helpful, the one that comes to mind first is for rifle length uppers to have a H2 or H3 buffer if you're using a carbine length buffer tube, as the H3 is close in weight to a rifle length buffer. These are gas guns, so they operate in a narrow range and different buffers are an easy way for everyone who doesn't want to go down the adjustable gas block path to help balance impulse vs. extraction.

 

[George44]

Buffer

My Colt 6920 came from the factory with a H Buffer. I have put approx. 800 rounds thru it with no stoppages. It works fine why change?