The Rosco 5.56 NATO/300 BLK Bolt Carrier Group in Phosphate Black (brand part no. ROS-BCG-002) is built to meet the demands of modern carbine shooters who need a BCG that just works, shot after shot. It’s phosphate coated with a chrome-lined gas key and bolt channel, full-auto rated, and properly staked to meet MIL specifications, with bolts shot-peened and MP-tested to confirm they’re free of flaws before they ever reach a rifle. Rosco partners with Microbest for the phosphate coating process, ensuring the finish holds up to real-world duty and range use, and every bolt is matched to its carrier for extreme accuracy and reliability. Rosco incorporated direct feedback from consumers and military end users into this design, delivering a BCG built to withstand full-auto firing and tough use rather than a bare-minimum spec part.

Key Specifications

• Compatible with 5.56 NATO and .300 BLK chamberings.
• Finished in phosphate coating partnered with Microbest.
• Features a chrome-lined gas key and bolt channel.
• Full-auto rated and properly staked to MIL specifications.
• Bolts are shot-peened and MP-tested for quality.
• Bolts are matched to the carrier for accuracy and reliability.

Frequently Asked Questions

Is this BCG rated for full-auto use? Yes, it’s full-auto rated and properly staked to meet MIL specifications.

What calibers is this BCG compatible with? It’s built for 5.56 NATO and .300 BLK chamberings.

Is the gas key chrome lined? Yes, the gas key and bolt channel are chrome lined for durability.

Buy the Rosco Bolt Carrier Group

Order it from our Lubbock, Texas gun shop for fast, direct shipping to your door, and drop in a BCG built for hard, reliable use.

Shop more from Rosco Manufacturing and browse our full AR bolt carrier groups selection.