Welcome to Palmetto State Armory!
A proprietary blend of Hammer forged chrome molly vanadium made by FN that is referred to as "Machine Gun Steel" by virtue of its use in FN's M249 and M240 weapons. The hammer forging process work hardens the steel, making it more durable. In addition, the chrome process for the bore allows for a lining almost twice as thick as a standard M16 for enhanced durability. Chambered in 5.56 NATO, with a 1/7 twist, M4 barrel extension, and a carbine-length gas system. The M4A1 profile barrel has more material under the handguards for better heat management over the M4 profile and is Mil-spec phosphate coated, High Pressure tested and Magnetic Particle inspected.
Also available as a barrel assembly, which includes a barrel nut and taper pinned stripped front sight base.
Please check the barrel closely for any irregularities. It is the builder's responsibility to check headspace before assembling.
In the unlikely event you have an issue with a barrel, STOP AND DO NOT ASSEMBLE. Contact Customer Service.