Proof Research PR15 PXT Steel AR Barrel Features The Proof Research PR15 PXT Steel AR Barrel is chambered in 6mm ARC and built with a 1:7.5 twist rate to stabilize the heavier high ballistic coefficient bullets that make the cartridge effective at extended range. The stainless steel construction offers corrosion resistance and a smoother finish compared to standard chrome moly barrels which can translate into improved accuracy potential over the barrel s service life. A .750 gas block diameter and standard 5-groove rifling make this barrel compatible with common AR-15 upper assemblies and gas block options. The 5/8x24 threaded muzzle accepts a wide range of muzzle devices or suppressors for the 6mm ARC cartridge. At 20 in length this rifle-plus-length barrel is suited to shooters who want to maximize velocity and effective range from the 6mm ARC cartridge whether for competition hunting or long-range practice. Proof Research built its reputation on precision rifle barrels and this steel AR barrel extends that manufacturing standard to the AR-15 platform at a more accessible price point than its carbon fiber offerings. Builders upgrading an existing 6mm ARC upper or starting a new build will find this barrel a straightforward drop-in option. This Proof Research PR15 PXT barrel is available for sale at GrabAGun for AR-15 shooters seeking proven 6mm ARC accuracy. Proof Research PR15 PXT Steel AR Barrel Specifications Manufacturer: Proof Research Model: PR15 PXT Steel AR Barrel Caliber: 6mm ARC Compatible Hosts: AR-15 Barrel Finish: Stainless Barrel Material: Steel Twist: 1:7.5 Diameter: .750 Grooves: 5 Thread Pattern: 5/8x24 Barrel Length: 20 Weight: 1 lb. 12 oz. Available At: GrabAGun