AR15 / M16 Auto Bolt Carrier Group MPI – Melonite Nitride
Our bolt carrier groups are engineered and designed to the highest tolerances. The unique Melonite Nitride finish ensures long term durability and lubrication. Each BCG incorporates our MPI “bionic bolt” which has exceeded 50,000 rounds in full auto, fully suppressed testing without fail.
Carrier: Melonite Nitride coated 8620 heat treated (case hardened to SAE-AMS-6875).
Bolt: Melonite Nitride coated 9310 heat treated (case hardened to SAE-AMS-6875) with additional cryo freeze for extra strength. Shot peened precision ground diameters. Magnetic Particle Inspected to ASTM E1444 aircraft quality inspection procedure for molecular soundness and longer life of the Bolt. 3 pc. stainless steel Gas rings per Mil-Spec.
Extractors: Phosphated aircraft quality alloy steel shot peened. Heat treated to military drawing specification SAE-AMS-6875.
Gas key: Melonite Nitride coated Gas key, aircraft quality steel heat treated. Gas key bolt, grade 8 fully knurled.
Cam pins: Phosphated, heat treated & precision machined.
Firing pin: Chrome lined & heat treated. Machined and precision ground for accuracy.
Ejector: Precision machined, heat treated & phosphated.