Our 5.56 chambered 11.75 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.
Material 4150 Chrome Moly Vanadium
Finish Black Nitride Corrosion Resistant
Gas System Length Carbine
Gas Block Journal .750"
Twist Rate 1:7 inches
Muzzle 1/2x28 Threaded
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.