FN America manufactures this 18″ barrel using U.S. Chrome Moly Vanadium material per Mil-B-11595E specifications, featuring button rifled construction in M16 styling. Each barrel undergoes High Pressure Testing (HPT) and Magnetic Particle Inspection (MPI) to verify it is free of micro stresses or flaws. The mil-spec steel construction is finished in black manganese phosphate for external corrosion and oxidation resistance.
Chambered in .223 Rem / 5.56x45mm, the barrel incorporates a chrome lined bore and chamber that resist corrosion and heat erosion to extend barrel life. The design includes M4 style feed ramps and barrel extension for consistent feeding, paired with a chrome lined chamber and feed ramp for reliable operation. The muzzle is threaded 1/2″ x 28 with a 1:7 RH twist rate, compatible with the 18″ Government Rifle profile and rifle length gas system.
This FN America component delivers mil-spec reliability for AR-platform rifle builds.
