The Rosco Manufacturing 5.56/300 BLK Bolt Carrier Group, Black Phosphate (brand part no. ROS-BCG-002) is built from stainless steel and finished in black phosphate for a durable, low-maintenance coating. The gas key and bolt channel are chrome-lined for smoother cycling and easier cleaning, the group is full-auto rated for hard use, and the gas key is properly staked to prevent it from loosening under sustained fire. Each bolt is individually matched to its barrel rather than mass-fit, giving tighter headspace consistency than a generic BCG. For 5.56 and .300 Blackout shooters who want a duty-grade bolt carrier group, this bolt carrier group is built to run hard.

Key Specifications

• Compatible with 5.56x45mm NATO and .300 AAC Blackout.
• Finished in black phosphate.
• Machined from stainless steel.
• Chrome-lined gas key for smoother cycling.
• Chrome-lined bolt channel for easier cleaning.
• Full-auto rated for hard, sustained use.
• Gas key is properly staked to prevent loosening.
• Each bolt is individually matched to its barrel for tighter headspace consistency.

Frequently Asked Questions

Is this bolt carrier group full-auto rated? Yes, it is full-auto rated for hard, sustained use.

Does it work in both 5.56 and .300 Blackout uppers? Yes, it is built to work with both 5.56x45mm NATO and .300 AAC Blackout.

Buy the Rosco Manufacturing 5.56/300 BLK Bolt Carrier Group, Black Phosphate

A properly staked gas key and barrel-matched bolt give this BCG the fit and durability of a genuine duty-grade part. Order it from our Lubbock, Texas gun shop for fast, insured shipping.