Rosco Manufacturing 5.56 NATO / 300 BLK BCG – Phosphate Black

The Rosco Manufacturing 5.56 NATO / 300 BLK Bolt Carrier Group is a mil-spec replacement or spare BCG designed for AR-15 platform rifles chambered in 5.56 NATO or 300 Blackout. This is a fully assembled, complete carrier group ready to install—ideal for builders completing a new upper or shooters stocking a spare for training and competition use. The phosphate finish provides proven corrosion resistance and reduces friction during cycling.

Machined from 8620 steel with a properly staked gas key, this BCG is finished in black phosphate (parkerized) for durability under field conditions. Installation is drop-in for any mil-spec AR-15 upper receiver. Includes bolt, carrier, cam pin, and firing pin assembly.

• Part Type: Bolt Carrier Group
• Compatible Firearms: AR-15 platform rifles in 5.56 NATO and 300 Blackout
• Material: 8620 steel carrier, Carpenter 158 steel bolt
• Finish: Phosphate (black)
• Installation: Drop-in
• Includes: Bolt, carrier, cam pin, firing pin, gas key (staked)