Seekins Precision barrels live up to the company’s name. Precision CNC machined to match grade specifications from the best quality 416 stainless steel blanks available, each barrel is inspected no less than four times to guarantee maximum accuracy and reliability. Perfect for building an AR pistol or short barreled rifle, Seekins Precision barrels are built to match grade tolerances. Premium stainless steel blanks are precision machined and inspected guaranteeing perfect concentricity and alignment for maximum accuracy potential. Each barrel has a non-glare bead blast finish which is then ArmorBlak coated and threaded for applicable muzzle devices. Threads 5/8-24 for the .300 Blackout. 5R button rifling and 1:7 twist. Made as a drop in replacement barrel for any mil-spec upper receiver. The .300 Blackout has become the preferred round for suppressed ARs. The barrel uses a pistol length gas system. All Seekins Precision barrels features the unique gas block alignment dimple for quick and easy installation of any .750″ gas block. For optimum rifle performance, use the Seekins Precision Low Profile Adjustable Gas Block for easy tuning of the gas system for your specific ammunition.