Shop › ROSCO 556NATO/300BLK BCG MELONITE BK ROSCO 556NATO/300BLK BCG MELONITE BK $140.00 Rosco Manufacturing Bolt Carrier Group, 556NATO/300 Blackout, Fits AR-15, Melonite Finish, Black ROS-BCG-001 Quantity: Add To Cart Added! Rosco Manufacturing Bolt Carrier Group, 556NATO/300 Blackout, Fits AR-15, Melonite Finish, Black ROS-BCG-001