So I've done some internet searching and some searching here and have not found much of an answer to a question or two rattling around in my head.

I just found 5.5 oz buffer in my box or AR parts as well as an 11" buffer spring (37 coils). I've concluded these are a 9mm buffer and a carbine length spring. I am planning a pistol lower build, using a 7.5" pistol buffer tube. I'll be using a 10" 300BLK upper on the build (with pistol length gas tube). Long windedly, can I (should I) use the 5.5oz buffer? Trade it for an H2 buffer? Any experience or thoughts with that type of set up?

On another note, I function tested the upper on my SBR'ed lower and it was fun to shoot. The 147 gr factory ammo cycled fine and now I'm looking forward to shooting subs through my YHM Ti Phantom....

Norseman