NBS .223/5.56 C158 Bolt Carrier Group Black Nitride

The NBS .223/5.56 Black Nitride Bolt Carrier Group was designed with strength in mind. Starting with the C158 Steel Bolt, this bolt has been heat treated, shot peened, precision ground and magnetic particle inspected. This NBS BCG (Bolt Carrier Group) has been Nitrided, so that it can provide a long-lasting experience, and provide a significant upgrade to your AR-15. These bolts have also been Magnetic Particle Inspected and have been made to Mil-Spec Standards. It also has Mil-Spec 8740 Steel hard-chromed Firing Pins, Mil-Spec Gas Keys with Grade-8 screws that are staked and sealed with Permatex No.3. Plus, with the AR15Discounts satisfaction guarantee, you can buy your AR build components without apprehension. Our guarantee says if you are unhappy for any reason, you can send it back to us within 30 days for a full refund. No worries. NOTE- The Salt Black Nitride BCG offers the dark, subdued finish that doesn't change the specs of the Bolt Carrier, but it still makes the outside of the Bolt Carrier harder. This treatment increases the longevity of the part, makes it extremely wear resistant and durable, and this treatment protects the part from corrosion. Technical Specs: * Gas system: Direct Impingement * Caliber: 5.56x45mm NATO/.223 Rem, .300 Blackout * Finish: Salt Black Nitride * Bolt: C158 Steel * Carrier: 8620 Aircraft Grade Steel * Extractor: Shot Peened and Case Hardened D2 Tool Steel * Firing Pin: Mil-spec 8740 steel with hard chrome finish * Gas Key: Mil-Spec w/ properly staked Grade-8 screws & Permatex No. 3 sealed * Cam Pin: 8620 Steel w/ Black Nitride Finish * Quality Control: MPI Inspected for QC