Description These 21″ AR-15 6mm ARC barrels are blackened 416 stainless steel, 1:7.7 twist, rifle length gas system, .750″ gas block journal, with the muzzle threaded 5/8-24. These are head spaced for use with .136″ deep bolt pockets which is standard for the 6.5 Grendel/6 ARC. You can not use a bolt with a .125″ deep bolt pocket, like what is usually used with a 7.62×39 barrel. Tromix typically engraves the caliber and twist at the 6 O’clock position, but these particular barrels have the engraving at 5 O’clock. Barrel weight is 2.62 pounds. SB 704 applies to all California sales – Must ship to FFL.
