LBE Unlimited M16BCG-NIB Complete BCG 5.56x45mm NATO, Nickel Boron Coated 8620 Steel, Full Auto Rated For AR Platform

M16 Complete Bolt Carrier Group Nickel Boron Bolt Material 9310 Tool Steel, Carrier 8620 Steel, Staked Gas Key, NiB Coated, Includes Firing Pin, Retaining Pin, Cam Pin, Extractor, Bolt Gas Rings