Fail Zero 5.56 NATO Black Nitride AR-15 Bolt Carrier Group

The Fail Zero AR-15 Bolt Carrier Group is a complete, drop-in BCG chambered in 5.56 NATO and engineered for reliable cycling in mil-spec AR-15, M16, and M4 upper receivers.

Built around an 8620 steel carrier and a steel bolt, this BCG is finished in black nitride across all critical wear surfaces. The black nitride coating delivers excellent lubricity, corrosion resistance, and simplified maintenance, making it a strong choice for duty, training, and hard-use rifles.

Fully assembled and ready to install, the Fail Zero BCG features standard AR-15 bolt carrier geometry and is designed for semi-automatic platforms. Overall dimensions measure approximately 1.75 x 3.80 x 10.95 in.