The ballistics advantage 14.5" 5.56 government profile midlength ar 15 modern series barrel is machined from 4150 chrome moly vanadium steel with a qpq corrosion resistant finish and qpq coated m4 feed ramp extension.*all nfa/atf rules apply.You may use this barrel with a lower receiver that is a registered sbr, machine gun, or pistol.Possession of this barrel along with a non-nfa lower receiver is prohibited, except when installed on a pistol configuration firearm.Caliber Or Gauge: 223 Remington/5.56 NATOLength: 14.50"Model: AR BarrelTwist: 1:7"Sights: NoneBore Type: RifledFinish: QPQ Corrosion ResistantType: All PurposeBarrel Type: Midlength Government ProfileAmmo Type: TacticalBarrel Features: 1/2"-28 tpi