Hey guys,
I am working on putting together my 2nd AR. I already have a BCM lower, and a BCM upper is on the way. The upper I ordered is a 16" mid-length.
My question is about buffer weight… The BCM lower is marketed as a “M4” lower, so it would make sense for them to include an H buffer, as M4s use the carbine length gas system. However, I will be using a mid-length gas system, as well as a BCM auto bolt carrier.
So, with the lower gas pressure of the mid-length system and the heavier (than semi) auto bolt carrier, is an H buffer still the right choice?
Thanks for any input. Just want to make sure I have my rifle set up correctly.
its kinda weird I have two rifles both with midlength gas systems, auto BCGs, H buffers. However one of them ejects casings too late around 2 oclock and one of them ejects perfect at 4oclock. So I swapped the 2oclocker with a carbine buffer to bring it back towards 3-4oclock. The 2oclock was using a spring I got from G&R. Only reason I could think of why they were different. H buffer is a good starting point.
Ive got the same question. Id say the standard weight should be fine. The Colt 6920 I believe ships with an H buffer. So with less gas, Id say a standard weight would be fine??
Both my of BCM middy’s run great, and are soft shooting with a standard carbine spring, and H buffer.
H should get you in the ballpark, and very marginal price increase over the CAR buffer.
This is what BCM recommends with good milspec ammo. Otherwise, if you feed it lower pressure ammo, they say use a CAR buffer.