Proof Research Barrel Features The Proof Research Barrel is machined in stainless steel with a 1:10 inch twist rate suited to a wide range of .308 Win bullet weights giving shooters flexibility whether they re loading lighter match projectiles or heavier hunting rounds. Built to a rifle-length gas system with a .750 inch gas journal diameter the barrel is designed to integrate cleanly with standard AR-10 pattern gas blocks and handguards without requiring nonstandard parts. The 5/8x24 threaded muzzle accepts a wide range of muzzle brakes compensators and suppressors giving builders flexibility to configure the rifle for their intended use. Proof Research s reputation for precision-cut rifling and tight chamber tolerances carries through into this barrel delivering the kind of accuracy serious AR-10 shooters expect. At 18 inches this barrel length strikes a balance between the reduced weight and improved maneuverability of a shorter barrel and the retained velocity of a longer one making it well suited to both hunting and precision rifle applications. Weighing approximately 3 pounds 1 ounce it keeps the completed rifle reasonably balanced compared to heavier bull-profile options aiding offhand handling during a long day at the range or in the field. The stainless steel construction offers strong corrosion resistance and a clean consistent finish that pairs well with a variety of receiver and handguard finishes so the barrel holds up to repeated use without sacrificing its appearance. For AR-10 builders and gunsmiths looking to upgrade accuracy without adding excessive weight this Proof Research barrel is a proven precision-built option for a .308 Win rifle build. Proof Research PR10 Barrel Specifications Brand: Proof Research Caliber: .308 Win Barrel Length: 18 Barrel Finish: Stainless Barrel Material: Steel Twist Rate: 1:10 Thread Pattern: 5/8x24 Gas System: Rifle Length Gas Journal Diameter: .750 Weight: 3 lbs 1 oz Available At: GrabAGun