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 coating Gas Key: 4130 Steel attached with Grade 8 hardware and properly staked Firing Pin: Machined from 8740 steel and hard chrome coated Forward Assist serrations Laser engraved Aero Precision logo Carrier fits AR .308 compatible style AR Uppers and RiflesBolt Features: Material: Case Hardened 9310 Steel Finish: All bolt components are shot peened and phosphate coated Extractor: Machined from 4340 Steel with double o-rings and double springs Magnetic Particle Inspected and High Pressure Tested High 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 carrier Complete bolt Firing pin Cam pin Retaining pin