WMD Guns, Bolt Carrier Group, Carrier Group without Hammer, Nib-X Finish, 7.62x39 7.62x39 NiB-X coating Bolt - Case hardened 9310, shot peened, magnetic particle inspected Extractor - Manufactured, heat-treated, and hardened Firing Pin - Manufactured, heat-treated, hardened, chromed and certified per Government drawings Gas Key - Hardened to USGI specifications and attached using grade 8 hardened fasteners Cam Pin - Manufactured, heat treated, hardened and certified per government drawing Carrier - M4/16 style full auto (heavier) functions in AR15 and M4/16 platforms, 8620 material, heat treated and case hardened Manufactured by Defense Industrial Base suppliers to WMD's exacting specifications to provide the best BCG available, these BCGs are specifically engineered for NiB-X nickel boron coating to provide long life, high reliability and easy cleaning and maintenance. The BCG components are coated and polished to reduce fouling adherence. Coating is guaranteed for life against chipping, spalling or flaking. Over 30K rounds in Government protocol endurance testing did not wear the coating off. Especially beneficial in short barrel setups and suppressed platforms.