AR-STONER AR-15 Bolt Carrier Group 5.56x45mm NATO Nickel Boron

The AR-STONER Nickel Boron Bolt Carrier Group is a great option for your next 223 Remington or 5.56 AR-15 Build. Machined to strict mil-spec tolerances, this BCG is drop-in ready. The Nickel Boron finish provides enhanced reliability and is more resistant to wear. The EXO NiB breakthrough technology creates a permanently lubricious surface, harder than the substrate itself, which eliminates the need for grease, oil, or any wet lubrication for the life of the weapon. Unlike films, conventional coatings and applied lubricants, it will never rub off, never flake off, never build up crud. EXO Technology eliminates wet-lubrication failures of critical components, giving you an "active weapon advantage" under all conditions.