Description The CMMG MK3 Bolt Carrier Group is a complete bolt carrier assembly designed for AR-style rifles chambered in .308 / 7.62 NATO. It is constructed from steel and finished in black phosphate, and the carrier is chrome-lined for added surface protection. The assembly includes a 9310 steel bolt and an S7 tool steel extractor, configured for direct installation in compatible AR .308 platforms. Intended for maintenance, repair, or building projects, the MK3 BCG provides OEM-style form and fit for its intended applications. Key Specifications The cartridge compatibility is .308 / 7.62 NATO. The product type is a Bolt Carrier Group. The configuration is listed as Complete. The primary material is Steel. The exterior finish is Black Phosphate. The carrier features a Chrome Lined surface treatment. The bolt is made from 9310 Steel. The carrier material is 8620 Steel. The extractor is made from S7 Tool Steel with a phosphate finish. Built with serviceable materials and manufacturer-standard dimensions, the CMMG MK3 BCG is a practical option for those restoring or assembling AR .308 platforms. Its combination of steel components, chrome-lined carrier, and protective phosphate finishes delivers a straightforward, durable solution for routine use and installation in compatible systems.
