These 5.56 / 300 BLK Bolt Carrier Groups are Phosphate Coated with Chrome Lined Gas Key & Bolt Channel, Full-Auto rated, properly staked, and the bolts are Matched to the barrel. The Nitride version features a melonite coating for extended performance. The Rosco Phosphate and Nitride Bolt Carrier Groups are designed to meet the modern-day carbine shooters requirements. They have also balanced input from their consumers and military end users in order to bring you the product you need, not just the one Rosco wants to sell you. All Rosco BCG's are to MIL Specification and have a properly staked gas key along with a chrome lined coating for extended performance. They also feat Mfg: Rosco Manufacturing
