The AB Arms PRO Advanced Rifle Bolt Carrier Group is specially made to have exacting tolerances and surface finishes and built to Mil-Spec dimensions. 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 is the perfect addition to any MSR.
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
