BCM® (MPI) complete bolt carrier group is fully assembled.
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 insure 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, BCM Extractor Spring, and is HPT (High Pressure Tested) and MPI (Magnetic Particle Inspected).
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.
- Milspec Carpenter No. 158® steel
- HPT Bolt (High Pressure Tested/ Proof)
- MPI Bolt (Magnetic Particle Inspected)
- Shot Peened Bolt
- Chrome Lined Carrier (AUTO)
- Chrome Lined Gas Key
- Gas Key Hardened to USGI Specifications
- Grade 8 Hardened Fasteners
- Key Staked Per Mil-Spec
- Tool Steel Extractor
- BCM Extractor Spring
- Black Extractor Insert
- Mil-Spec Crane O-Ring