The Ballistic Advantage 14.5" 5.56 M4 Carbine-Length Barrel from the Modern Series is built for reliability and durability. Machined from 4150 Chrome Moly Vanadium steel, it features a QPQ (Quench Polish Quench) corrosion-resistant finish for long-lasting protection in harsh conditions. The barrel extension includes M4 feed ramps, also QPQ coated, to ensure smooth and consistent feeding. This barrel is ideal for duty or tactical use and offers the rugged performance you'd expect from a trusted name. *All NFA/ATF rules apply: this barrel may only be used with a registered SBR, machine gun, or pistol lower. Possession with a non-NFA lower is prohibited unless installed on a pistol configuration.