Shaw Barrels AR-15 6mm ARC 18" HBar 416R Stainless Barrel - 5/8x24

The Shaw Barrels AR-15 6mm ARC 18" HBar is a premium drop-in replacement barrel built around the efficient 6mm ARC (Advanced Rifle Cartridge) chambering. Machined from 416R stainless steel with a non-reflective matte finish, this barrel is engineered to deliver the long-range accuracy that 6mm ARC was designed for while standing up to repeated fire on the AR-15 platform.

The barrel features a heavy-duty HBar (Heavy Barrel) contour that resists point-of-impact shift during extended strings of fire, making it a strong fit for precision-leaning 6mm ARC builds. A 1:7.5" twist rate with 6-groove rifling provides the rotational velocity needed to stabilize modern long, high-BC 6mm projectiles, while the 18" length offers a balanced compromise between velocity, weight, and handling for general-purpose AR-15 use.

Threading comes in at 5/8x24, the standard pitch for 6mm ARC and other modern AR-15 cartridges, ready to accept a wide range of muzzle devices and suppressors. Like the rest of Shaw's 6mm ARC lineup, this barrel is crafted by Shaw's experienced barrel makers from quality 416R stainless steel.