Great Lakes Firearms & Ammo AR-15 Bolt Carrier Group, .223/5.56 NATO/.300 AAC Blackout

The Great Lakes Firearms & Ammo Bolt Carrier Group (brand part number 556BCG) is a steel BCG built for standard AR-15 rifles chambered in .223 Remington or 5.56 NATO, and it shares the same bolt face used by .300 AAC Blackout uppers, giving one carrier group broad compatibility across the two most common AR-15 chamberings. Great Lakes finishes the whole assembly in a black salt bath nitride coating for corrosion resistance and smoother cycling than a standard phosphate finish. It’s a straightforward drop-in for shooters building or upgrading an AR-15 upper who want a durable, easy-running carrier group.

Key Specifications

• Compatible with .223 Remington and 5.56 NATO chambered AR-15 uppers.
• Also compatible with .300 AAC Blackout uppers, sharing the same bolt face.
• Machined from steel for durability under repeated cycling.
• Finished with a black salt bath nitride coating for corrosion resistance.
• Built to fit standard AR-15 rifles and uppers.

Frequently Asked Questions

Does this work with .300 AAC Blackout? Yes, it shares the same bolt face used by 5.56 NATO and .300 AAC Blackout uppers.

What finish does it use? A black salt bath nitride coating for corrosion resistance and smoother cycling.

Buy the Great Lakes Firearms & Ammo AR-15 Bolt Carrier Group

Upgrade your AR-15 upper with a durable, multi-caliber-compatible BCG. Order it from our Great Lakes Firearms & Ammo lineup, part of our gun parts kits selection, at our Lubbock, Texas gun shop for fast, direct shipping.