Barrel: 14.5 in barrel chambered in 5.56 NATO, 1:7 twist, M4 barrel extension, and a mid-length gas system. Barrel is finished with a Geissele MK14 DDC 13.5 in M-LOK handguard and a B&T Assault 3 Prong 1/2x28 muzzle device. Hammer forged chrome moly vanadium used by FN Manufacturing, marketed as Machine Gun Steel. Pin/Weld setup.