FN AR-15 5.56x45mm NATO 18" Rifle Length Cold Hammer Forged Chrome Lined Barrel

The FN 36423 AR-15 barrel is an 18" cold hammer forged replacement barrel chambered in 5.56x45mm NATO (also fully compatible with .223 Remington). Manufactured by FN America, this is the same hammer-forged barrel used on FN's factory AR-15 rifles, built to mil-spec dimensions for a drop-in fit on standard AR-15 upper receivers.

The bore and chamber are chrome lined for extended service life and improved resistance to heat and corrosion, while the exterior is finished in a black manganese phosphate coating to match factory FN rifle specs. The barrel is gas-ported for a rifle length gas system and is designed to work with a standard .750" gas block.

Muzzle threading is 1/2x28 for direct compatibility with the vast majority of 5.56 muzzle devices, flash hiders, brakes, and suppressors. Whether you are building a precision AR-15, refreshing a worn upper, or assembling a custom rifle-length carbine, this new, unused factory replacement barrel is a high-quality foundation for any 5.56 AR-15 project.