Our .308 / 7.62 Bolt Carrier Group is the perfect firing mechanism for your big-bore rifle build. This high quality BCG features a mil-spec phosphate finish, is MPI/HPT and now includes a laser engraved Aero Precision 'A' logo!Carrier Features:Machined from 8620 Tool Steel (Carrier) and 9310 Steel (Bolt)Finish: Mil-spec Phosphate coatingGas Key: 4130 Steel attached with Grade 8 hardware and properly stakedFiring Pin: Machined from 8740 steel and hard chrome coatedForward Assist serrationsLaser engraved Aero Precision logoCarrier fits AR .308 compatible style AR Uppers and RiflesBolt Features:Material: Case Hardened 9310 SteelFinish: All bolt components are shot peened and phosphate coatedExtractor: Machined from 4340 Steel with double o-rings and double springsMagnetic Particle Inspected and High Pressure TestedHigh pressure bolt - external surfaces are CNC ground after heat treat for a precision fit and firing pin hole diameter is reduced to .070"Multi-caliber bolt designed to function with .308, 7.62x51, .338 Federal and other .308 based cartridges.BCG Includes:Bolt carrierComplete boltFiring pinCam pinRetaining pin