FN America Barrel M4 Bb 16" Carbine Length 556

The FN America Barrel M4 16" Carbine Length 556 is a precision rifle barrel engineered for AR-platform builds requiring dependable accuracy and rapid cyclic performance. This 16-inch barrel features a 1:7 twist rate optimized for modern 5.56 NATO ammunition, delivering the velocity-to-length balance operators expect from a carbine-length gas system configuration. Button broached rifling ensures consistent bore concentricity and extended barrel life under sustained fire.

The 1:7 twist specification stabilizes heavier projectiles (62–77 grain), making this barrel suitable for both training and duty ammunition. Carbine-length gas tube geometry reduces carrier velocity and extends component life compared to mid-length or rifle-length systems, while maintaining the reliability required for law enforcement and military service weapons. The matte black finish provides corrosion resistance without reflective surfaces. At 2.31 lbs, the barrel contributes minimal weight to upper-receiver assemblies while maintaining the structural rigidity necessary for precision shooting.

This barrel is designed for shooters building or upgrading AR-15 rifles where proven FN engineering meets practical carbine length configuration. It fits standard AR-15 upper receivers and works with mil-spec or commercial gas tubes. Precision builders, law enforcement armors, and serious carbine users favor FN barrels for their dimensional consistency and field reliability across varied duty conditions.

The 16-inch barrel length balances velocity and maneuverability—longer than pistol-length builds but shorter than mid-length or rifle-length systems, making it the standard for patrol carbines, close-quarters duty rifles, and compact training platforms. The FN America Barrel M4 556 represents a no-compromise foundation component for operators who demand proven performance.