Battle Arms Development BAD-BCG-M16 223Rem/5.56NATO/300BO Black Nitride Steel AR15/M16/M4

Bolt Carrier: 8620 Steel Case Hardened, Machined from Billet, Firing Pin: 17-4 H-900 Steel, Center-less Ground, Gas Key: 4140 Steel with Grade 8 Screws, Properly Staked, Machined from Billet, Cam Pin: 4140 Hardened Steel, Finish: Black Nitride finished with an ultra-hard, corrosion-resistant top surface layer for wear resistance and minimal need for lubricants. Bolt: 9130 steel Shot Peened, Mil-Spec Dimensions, CNC Ground After Heat Treat, Black Nitride Finished MPI/HPT, Extractor: 4140 Billet, Manganese Phosphate Finished for Positive Grip