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 heavy buffers in xm177e2
jeebus  [Member]
4/23/2012 2:36:17 AM
Should I plan on using a heavy buffer in my xm177e2 clone? I've got an m16 style bolt already, but being an 11.5" barrel should I consider it? If so what weight? And which brand is the best and most reasonable pricewise?
stevejness  [Team Member]
4/23/2012 3:04:56 AM
If you have to buy a new buffer regardless, I'd start with an H2 and not worry about it.

But if you already have some standard buffers laying around, I'd try one of those first. 11.5" barrels don't seem to have as many issues as the sub-10" ones sometimes have.
jeebus  [Member]
4/23/2012 4:10:09 AM
I do have a standard so i guess ill try it. A bit worried about the harsh return action
mike62  [Team Member]
4/23/2012 10:59:55 AM
Standard buffer didn't work in mine - I will be curious to hear how yours does. My H2 ready to go but I haven't hit the range with it yet... maybe this week.
uxb  [Team Member]
4/23/2012 11:45:34 AM
An "H" buffer will work fine in 10.0" - 11.5" gas systems. No need to go to an H2.

Use H2s for 7.5" barrels or 9mm 10.5" systems.
LRRPF52  [Team Member]
4/23/2012 1:16:45 PM
The buffer weight isn't the only variable. It's a balance between the buffer weight, bolt carrier weight, gas port diameter, projectile weights, and propellant charge of the cartridge.

I've had excellent reliability with two 11.5" guns that I owned in the past, running them with 55gr US-made, brass-cased ammo. I don't recall any malf's with them, and they had 2.9 oz buffers to the best of my knowledge.

I will also say that 11.5" barrels generate more velocity than most gun rag "experts" give them credit for, with both 55gr and 62gr pills at military loading pressures. M193 out of an 11.5" will scream along at only 90fps slower than a 14.5" barrel, which pushes M193 over 3000fps.

There is not a lot of practical difference in on-target performance that the shooter can recognize between an 11.5" and 14.5" gun.