This Noveske Bolt Carrier Group is DLC exterior coated to Noveske specification with chrome lined bore. Machined to USGI specifications. Carrier is made out of Aircraft grade, domestically sourced proprietary 8620 steel. 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 domestically manufactured Grade 8 fasteners and properly staked per Mil-Spec.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, extractor spring and washer, and is MPI (Magnetic Particle Inspected). All Noveske enhanced DLC Bolt Carrier Groups hand assembled and verified to meet Noveske specs for function, and quality. FeaturesDLC coated for exceptional surface hardness and lubrication, all while preserving a flexible coreCompatible with a full range of Mil-spec sub-components for seamless in...