12.5" 5.56 USGI Profile Carbine AR 15 Barrel

Our 5.56 chambered 12.5 inch USGI Profile Carbine Barrel is machined from 4150 Chrome Moly Vanadium steel with a Black Nitride Corrosion Resistant Finish and Black Nitride Corrosion Resistant coated M4 feed ramp extension. 4150 has a 0.50% carbon content and is used for barrels that need to be tougher, have more strength, and higher hardness than 4140 or 4130 can provide. It's a little less common and takes a little extra effort to machine but produces the right results. Additional Info Length 12.5" Material 4150 Chrome Moly Vanadium Profile Government Finish Black Nitride Corrosion Resistant Gas System Length Carbine Gas Block Journal .750" Twist Rate 1:7 inches Rifling 5R Muzzle 1/2x28 Threaded Weight 25oz All NFA/ATF Rules ApplyYou 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.