FN America Barrel M4 Bb 16" Carbine Length 556

The FN America Barrel M4 16" Carbine Length 556 is a precision rifle barrel designed for AR-platform builds that require dependable accuracy and rapid cyclic performance. This 16-inch barrel is specifically engineered for 5.56 NATO ammunition, making it an excellent choice for both training and duty use in various shooting scenarios.

Featuring a 1:7 twist rate, this barrel stabilizes heavier projectiles (62–77 grain) and is optimized for the velocity-to-length balance expected from a carbine-length gas system configuration. The button broached rifling ensures consistent bore concentricity and extends barrel life under sustained fire. Additionally, the carbine-length gas tube geometry reduces carrier velocity, enhancing component longevity while maintaining reliability.

This barrel is compatible with standard AR-15 upper receivers and works seamlessly with mil-spec or commercial gas tubes. Shooters building or upgrading AR-15 rifles will appreciate the proven FN engineering that meets practical carbine length configurations. Precision builders, law enforcement armors, and serious carbine users favor FN barrels for their dimensional consistency and field reliability across varied duty conditions.