Shaw Barrels AR-15 Barrel Features The Shaw Barrels AR-15 Barrel is chambered in 6mm ARC a cartridge purpose built for long range accuracy in the AR-15 platform and its 1 in 7.5 inch twist rate stabilizes the heavier higher ballistic coefficient bullets that make the cartridge effective at distance. The HBAR profile adds extra mass along the barrel for improved heat dissipation and reduced harmonic whip during strings of fire helping maintain accuracy as the barrel warms. A mid length gas system times the gas impulse for smoother cycling and reduced felt recoil compared to a carbine length system in the same barrel length. The 6.5 Grendel Type II / ARC bolt and headspace specification noted by the manufacturer means a compatible bolt is required though it is not included with this barrel. Machined from 416R stainless steel a material prized for its machinability and corrosion resistance the barrel holds tight tolerances that support consistent accuracy shot after shot. Its bead blast matte finish gives the barrel a non reflective surface that resists glare in the field while still showcasing the stainless steel underneath. The .750 inch gas block diameter and dimpled gas journal ensure a secure properly indexed gas block installation on this AR-15 pattern barrel. With a 5/8x24 threaded muzzle it is ready to accept a wide range of muzzle brakes flash hiders or suppressor mounts for a complete 6mm ARC build. Shaw Barrels AR-15 Barrel Specifications Manufacturer: Shaw Barrels Type: AR-15 Barrel Caliber: 6mm ARC Barrel Length: 12.50 Barrel Finish: Bead Blast Matte Barrel Material: 416R Stainless Steel Barrel Description: HBAR Profile Barrel Type: Mid-Length Twist Rate: 1:7.5 Gas Block Diameter: .750 Thread Pattern: 5/8x24 Weight: 1.70 lbs Available At: GrabAGun