Armalite AR-10 BCG Bolt Carrier Group (10501001) is constructed from 8620 steel, the Armalite AR-10® complete bolt carrier group is chrome lined and includes complete bolt assembly.

Chrome lined complete AR10 BCG / bolt carrier group includes complete bolt assembly.
AR-10 bolts and carriers have 8620 STEEL
Torque on gas key screws 55-inch lbs