AR-15 H2 Heavy Buffer AR-15 Carbine

A: Yes we run all our AR-15 BRA 7.62x39 rifles with an H2 buffer except our mid-length we tune with a carbine buffer. We have seen some 7.62x39 uppers that were so overgassed that customers were reporting having to use an H3.....that is super overgassed as H3 normally in this caliber cause short stroking. Tula Ammunition and Red Army are extremely hard on 7.62x39 bolt assemblies and extractors. We have tested these particular brands on many occasions and have found that cartridges tend to get stuck and/or casings do not shrink properly which causes undue stress on the extractors and the bolt lug next to the extractor. This will contribute to premature failures of these parts.
Barrel Extensions with a large wide single feed ramp with no middle lug does not support the bolt assembly properly. To see if one is overgassed we recommend shooting through a chronograph to get proper cyclic rates.