This M5 .308/7.62 bolt carrier is a firing mechanism for your big-bore rifle build. It features a mil-spec phosphate finish is made of steel chrome lined gas key and firing pin channel and has forward assist serrations. The bolt features double o-rings and springs is made of steel and has a multi-caliber bolt designed to function with .308 7.62×51 6.5 Creedmoor .338 Federal and other .308 based cartridges. Included is: a bolt carrier complete bolt firing pin cam pin retaining pin and an Aero Precision “A” logo.