BCM (MPI) complete bolt carrier group is fully assembled. (BCG)
Bolt carrier group (auto version) for your AR15, M16, or M4. Parkerized exterior and chrome lined inside carrier. Machined to USGI specifications. This M16/M4 carrier includes the proper Mil-Spec gas key. Gas key is chrome lined and heat treated per GI specifications. Gas key is secured to carrier via USGI domestic mfg. Grade 8 fasteners and properly staked per Mil-Specs. These properly hardened parts ensure a strong staking and proper gas system functioning.
Prior to shipping, all BCM Bolt Carrier Groups are test fired for function. As such, the Bolt Carrier Group will show handling marks consistent with these quality control procedures.