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 a forward assist serrations. The bolt features double o-rings and springs is made of steel and is 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 a Aero Precision “A” logo.