NBS AR-10 Left-Handed Bolt Carrier Group Black Nitride

This NBS Black Nitride .308 Complete BCG is compatible with any AR10, .308 or 7.62x51 rifle that follows the DPMS pattern. The carrier includes forward assist serrations and the bolt is (MPI) certified. Bolt: MPI Inspected 9310 Alloy Steel Hardened Steel Extractor Milspec Gas rings (3) Black Extractor Insert 2 Viton O-Rings Bolt Carrier: 8620 Steel Heavy Duty Full Cut Design Grade 8 Gas Key Screws, Staked Gas Key Material - 4140 Cam Pin: 8620 Steel Nitride Finish Firing Pin: Mil-Spec Firing Pin