FailZero AR-15 Semi-Auto .223 / 5.56 EXO Nickel Boron Bolt Carrier Group

Featuring wear-resistant nickel boron-coated components, the FailZero AR-15 .223 / 5.56 EXO Nickel Boron Bolt Carrier Group comes fully assembled and ready to install in most AR-15-pattern receivers. Featuring heavy-duty tool steel construction, this BCG includes a precision-machined bolt and extractor, bolt carrier, cam pin, carrier key, and firing pin for faithful, drop-in service right out of the box.