Proof Research PR15 PXT Steel AR Barrel Features The Proof Research PR15 PXT Steel AR Barrel combines advanced PXT rifling geometry with the performance and precision shooters expect from PROOF. PXT or PROOF Exponential Twist rethinks conventional twist progression by dramatically reducing rifling lead angle and smoothing projectile engagement into the bore. This reduces engraving force minimizes throat erosion and creates less felt torque during firing for improved recoil control and the ability to stay on target more effectively. In controlled testing PXT barrels have shown significant increases in barrel life while holding to the accuracy standards PROOF barrels are known for. Chambered in 6mm ARC with an 18 inch length and a 1:7.5 twist rate this stainless steel barrel is built on a rifle-length gas system for the AR-15 platform with a .750 inch gas journal and a .096 port size tuned for reliable cycling. The 5/8x24 threaded muzzle accepts a wide range of brakes compensators and suppressors giving builders flexibility in finishing out their rifle. Arriving fully chambered and ready for installation this barrel is an easy upgrade for shooters looking to refine an existing build or complete a new high-performance 6mm ARC rifle. The Proof Research AR Barrel is available for sale at GrabAGun for AR-15 builders seeking a precision stainless steel 6mm ARC barrel. 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 Barrel Description: Rifle +1 Length Twist: 1:7.5 Diameter: .750 Grooves: 5 Thread Pattern: 5/8x24 Barrel Length: 18 Weight: 1 lb 12 oz Available At: GrabAGun