The Liberty Fighting AR-15 Barrel from Sons of Liberty Gun Works is a 5.56x45mm NATO AR-15 barrel. It features a 5R rifled, 41v50 chrome moly barrel that is phosphate treated and chrome lined. This barrel uses a .223 Wylde chamber and a 1:7 twist. The barrel extension is DLC coated. It is dimpled for secure gas block installation and has a standard 1/2x28 muzzle threading for compatibility with muzzle devices and direct thread suppressors.