The bolt assembly is machined from the correct Mil-Spec Carpenter No. 158® steel, shot peened for increased strength. Also includes tool steel machined extractor and ejector, BCM Extractor Spring, and is HPT (High Pressure Tested) and MPI (Magnetic Particle Inspected).

Machined to USGI specifications, this M16/M4 carrier includes the proper Mil-Spec gas key. The gas key is chrome lined and heat treated, per GI specifications, secured to the carrier via USGI domestic manufacturing Grade 8 fasteners and properly staked per Military Specifications.