Buffers...H vs. H2...what I thought I knew...

Weapon: DDM4 V5 w/16" barrel and mid-length gas system.
Suppressor: Surefire 556-212 full-size mounted on 212FH.
Ammo: PMC XTAC M193
Buffers used: H, H2
Action springs: DD and Sprinco

I noticed, using the H2 buffer, MORE gas in my face, MORE recoil, and the ejected casings when I fired 3 rounds rapidly back to back ejected to the same place as they did with the H buffer. I say fired rapidly, because I have found that with a suppressor, if you fire slowly vs. rapidly, the cases tend to “move around” in the ejection pattern, so I fired both strings at the same cadence.

Function was 100% with both, and ejection pattern doesn’t mean anything, but one would expect it to change, I’d think. The main thing I’m confused with here is WHY is the H2 giving me more recoil and more gas in the face? With the H, I could crack off rounds without any gas, with the H2, rapid-fire strings would result in a bit of obnoxiousness.

*I noted no difference between the function of the two action springs.

(keeping in mind that I know very little)

Is there more resistance with the heavier buffer causing more force to be rebuffed rather than absorbed?

Sounds like the H2 isnt slowing it down enough for the right effect. Maybe try an H3 and see if it tames the recoil down a bit. If you rifle can push a heaver mass back with no problem, all it will do is increase the recoil. I have no Idea why you would get less gas from the H buffer as it should be the other way around. Doesn’t really sound like you have a problem though. As long as it doesn’t seem like the H buffer is beating your rifle up then just stick with it.

The H was doing fine. Rifle felt much better with the H. Violent and gassy with the H2, and yes, I verified both what was stamped on the buffer and what it felt like when I hefted it. I got them correct.

Do you have a small kitchen scale? I would definately weight the two buffers to verify the specs.

I agree to get exact weights but the H2 was notably heavier when I hefted it. It was a colt iirc.

I’m not an engineer and I try not to overthink stuff. I don’t really see how an H2 buffer would make the weapon more gassy. I can see how it would feel like more recoil, because there is more mass moving back and forth. We noticed this once when swapping a Vltor A5H3 to an A5H4. As it returned to battery and chambered another round round it seemed as if it was a little harsher.

I don’t notice now because of the addition of the LMT E-carrier which has everything running like hot butta’.

Could the heavier buffer be keeping the bolt closed longer, causing more gas to flow out from the vents in the carrier?

That might well be it!

I’m not quite sure why you WOULDN’T get more gas in the face with a heavier buffer…

Also, where is the gas coming from? Carrier? Charging handle?

Couldn’t it also be the reason for more felt recoil? I imagine if the bolt were locked up longer, it would impart more recoil to the firearm as less is imparted to the recoiling assembly. I’m just speculating though. I started a somewhat similar thread about suppressed port noise.

I’d say “the upper”. Everywhere. It’s all pressurized.

Roger that; makes sense.

I’m just trying to understand the physics of how buffer weight plays a part in the amount of gas to the face.

I don’t understand why some say that a heavier buffer = less gas.

I saw it as well as felt/breathed it and heard it. Much more of a “puff” and smoke from the upper area. It was a few inches in front of my face, so I can’t say where PRECISELY it came from, I just know I was seeing bigger puffs and experiencing “more”.

The theory would be the lock time would be longer so less would come out it into the receiver. The longer the bolt is forward the longer the gas is pressurized in the system and less time it has to enter the upper receiver. But its such a small amount it really wouldn’t be much difference. Dont forget when shooting suppressed it comes out of the chamber also, not just mainly the gas tube like un-suppressed.