Rosco 5.56 NATO / .300 Blackout Phosphate Bolt Carrier Group

Take your custom AR-15 build to the next level with the Rosco® 5.56 NATO / .300 Blackout Phosphate Bolt Carrier Group (BCG) from GunMag Warehouse. This fully-assembled and full-auto-rated BCG features an 8620 steel carrier and a properly staked and chrome-lined 4130 steel gas key with Grade 8 fasteners and a corrosion-resistant phosphate finish, ensuring reliable performance with minimal wear. The cam pin is machined from hardened 4340 steel construction, while the firing pin is 8740 steel, center-less ground and hard chrome coated, and built to Mil-Spec tolerances for a tighter lockup and enhanced performance under extreme conditions caused by full-auto fire. The MPI/HPT tested and shot-peened bolt is machined from 9310 steel, and the extractor is crafted of 4340 steel, yielding better accuracy and exceptional reliability. Plus, the ejector is constructed with S7 tool steel. Compatible with most Mil-Spec upper receivers (not included)