Alexander Arms 10.5" Upper

[rebby]

IIRC from my conversation with my gun writer friend who had a rather lengthy discussion with AA, AA only uses buffers and springs to run reliably both suppressed and non-suppressed.

Correct, they do not advocate using anything other than standard weight buffers and springs. Suppressed/non-suppressed is part of the reason for that.

FWIW, we usually buck that trend and install H2 buffers in all of our builds, Grendel's included (we're an authorized AA dealer).