American Built Arms Complete Bolt Carrier Group Nickel Boron Coated 5.56

American Built Arms Company Pro 5.56 Bolt Carrier Group BCG Nickel Boron Silver. These Bolt Carrier Groups by American Built Arms Company are built of 8620 steel and coated in Nickel Boron with a Nickel Boron coated bore so you'll need nearly no lubrication. The extractor of the American Built Arms Co PRO 5.56 BCG is made from aircraft grade E4140 steel and is coated in manganese phosphate to provide superior extraction during each fire. Drop in ready this AB Arms NiB Bolt Carrier Group BCG is the perfect addition to any MSR. Specifications for American Built Arms Company PRO 5.56 Bolt Carrier Group (BCG): Manufacturer: American Built Arms Company Color: Silver Finish: Nickel Boron Fabric/Material: Steel Cartridge: 5.56x45mm NATO Gun Make: AR Platform Hand: Right Condition: New Bolt Material: 9310 Steel Carrier Material: 8620 Steel Features of AB Arms PRO Advanced Rifle Bolt Carrier Group BCG 2AM-BCG-ABABCG: Bolt Carrier made of 8620 Steel Nickel Boron Coated with Nickel Boron Coated Bore M-16 Style with more mass for better functioning in semi or full auto rifles Gas Key made of 4130 Steel and Nickel Boron Coated Gas Key Screws - 4140 Steel properly staked per Mil-Spec requirements Cam Pin made of 4340 Steel Heat treated per Mil-Spec Requirements and Nickel Boron Coated Extractor made of Aircraft Quality E4140 Steel Heat treated and Shot Peened per Mil-Spec Requirements and Manganese Phosphate Coated per Mil-Spec Requirements Firing Pin made of AISI 8740 Steel and Chrome Coated Package Contents: American Built Arms Company PRO 5.56 Bolt Carrier Group 2AM-BCG-ABABCG American Built Arms Company ABABCGNiB: Pro 5.56 Bolt Carrier Group Nickel Boron Silver