The Dynacomp AK is machines from 416 Heat Treated Stainless Steel and has a matte Melonite finish. It is machined in standard Dynacomp configuration. It is compatible with 7.62x39mm, .308 cal, 6.8 SPC, 6.5 Grendel,5.45x39mm,5.56x45mm, and .22LR. It has 14x1 left hand threads.