FN AR15 premium button-rifled barrels are manufactured using U.S. Chrome Moly Vanadium material per Mil-B-11595E. Each barrel is High Pressure Tested (HPT) and Magnetic Particle Inspected (MPI) to ensure that it is free of micro stresses or flaws, resulting in consistency and quality in every barrel shipped from the factory. The bore and chamber are chrome lined to help resist corrosion and provide resistance to heat erosion, which greatly improves barrel life and reliable chambering / extraction. The M4 style feed ramps and barrel extension provide consistent feeding and the matte black Manganese Phosphate finish resists external corrosion and oxidation. Currently available in a chambering of 5.56 x 45mm in the following profiles and gas system lengths 10.5″ Government Carbine, 14.7″ Government Mid Length, 14.7″ M4 Carbine, 16″ M4 Carbine, 16″ Government Carbine, 16″ Government Mid Length, 18″ Government Rifle, 20″ Government Rifle.
- Length: 20″
- Material: Chrome Moly Vanadium
- Finish: Manganese Phosphate
- Twist Rate: 1:7 inches
- Gas System: Rifle Length
- Muzzle: 1/2×28 Threaded
- M4 feed ramps and barrel extension
- High Pressure Tested (HPT)
- Particle Inspected (MPI)
- Chrome Lined Bore