Shop › ROSCO 556NATO/300BLK BCG PHOS BLK ROSCO 556NATO/300BLK BCG PHOS BLK $145.00 Rosco Manufacturing Bolt Carrier Group, 556NATO/300 Blackout, Fits AR-15, Phosphate and Chrome lined Finish, Black ROS-BCG-002 Quantity: Add To Cart Added! Rosco Manufacturing Bolt Carrier Group, 556NATO/300 Blackout, Fits AR-15, Phosphate and Chrome lined Finish, Black ROS-BCG-002