DealPSA AR15 .223/5.56 Nitride/QPQ Bolt Carrier Group Bolt: Shot-peened 9310 steel, Nitride treated for longevity. Stainless Gas rings, Precision machined extractor, black extractor insert. Carrier: 8620 steel, heavy profile, nitride treated. Gas key is nitride treated, fastened with grade 8 screws, and staked to mil-specs. from Palmetto State Armory (Product 7789541) |