10.5" Government Barrel 5.56 .223 for AR-15 (Carbine) This 5.56 chambered 10.5 inch Government Profile Barrel is machined from 4150 Chrome Moly Vanadium steel with a QPQ Corrosion Resistant Finish and QPQ coated M4 feed ramp extension. This 10.5” barrel is a fully machined carbine-length barrel precision-crafted from 4150 Chrome Moly Vanadium, rifled with a 1:7 twist and QPQ coated inside and out. The result is an accurate barrel that stays that way without chipping or peeling coatings and little risk of damage from corrosion, regardless of your operating environment. Length - 10.5" Material - 4150 Chrome Moly Vanadium Profile - Government Finish - QPQ Corrosion Resistant Gas System Length - Carbine Gas Block Journal - .750" Twist Rate - 1:7 inches Muzzle - 1/2x28 Threaded Weight - 19oz Other Info - M4 feed ramps All NFA/ATF Rules Apply Depending on your state and local laws, you could use this barrel with a lower receiver that is a Registered SBR, or Pistol. Possession of this barrel along with a Non-NFA lower receiver may be Prohibited. We are not lawyers and the above information is not legal advise. Make sure you understand the most up to date federal, state and local laws before proceeding with this product. SKU: KM556105GOV UPC: 860006522170