Faxon Firearms FF556BCNITRIDE 5.56 NATO Black Nitride 9310 Steel AR-15 Bolt

The Faxon Firearms FF556BCNITRIDE is a precision-machined AR-15 bolt manufactured from 9310 tool steel and treated with a durable black nitride finish. Designed as a direct replacement bolt for the 5.56 NATO AR-15/M16 platform, this bolt is engineered for reliable cycling, long service life, and consistent function in demanding shooting conditions.

Faxon machines each bolt from 9310 tool steel, a premium alloy selected for its outstanding toughness and fatigue resistance under high-pressure firing cycles. The black nitride surface treatment increases surface hardness, reduces friction against the bolt carrier, and provides excellent corrosion protection, helping the bolt maintain smooth operation over extended use.

Built to standard AR-15 bolt dimensions, the FF556BCNITRIDE drops into 5.56 NATO and compatible .223 Remington upper receivers. Every bolt is MPI (Magnetic Particle Inspected) to verify structural integrity before it leaves the factory. Whether you are assembling a new build, replacing a worn bolt, or upgrading an existing rifle, this bolt delivers the consistent quality and dependability that Faxon Firearms is known for.