Micro-Best Full-Auto M-16 Chrome Lined Bolt Carrier Group
The Micro-Best Bolt Carrier Group (BCG) (auto version) for 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.
The bolt assembly is machined from the correct Mil-Spec Carpenter No. 158® steel, shot peened for increased strength, includes tool steel machined extractor and ejector, and is HPT (High Pressure Tested) and MPI (Magnetic Particle Inspected).
These Bolt groups are manufactured by Micro-Best, the oldest and largest OEM supplier of Mil-Spec BCG for many of the Govt. contracts.