Proof Research Lone Peak Arms 22 Creedmoor Threaded Rifle Barrel Sendero 18 in 8 Twist Pxt 5/8-24 Thread 2.5 Weight Carbon. PXT - PROOF Exponential Twist - is a complete rethinking of conventional rifling geometry and twist progression engineered to reduce engraving force minimize throat erosion and create a smoother transition as the projectile engages the rifling. Specifications for Proof Research Lone Peak Arms 22 Creedmoor Threaded Rifle Barrel: Manufacturer: Proof Research Caliber: .22 Creedmoor Barrel Twist Rate: 1-8 Firearms Threads Per Inch: 5/8x24 Gun Make: Lone Peak Gun Model: Lone Peak Fuzion Gun Type: Rifle Package Contents: Proof Research Lone Peak Arms 22Cm Threaded Rifle Barrel What firearm models does the manufacturer say Proof Research Lone Peak Arms 22 Creedmoor Threaded Rifle Barrel is compatible with? The manufacturer says that Proof Research Lone Peak Arms 22 Creedmoor Threaded Rifle Barrel is compatible with Lone Peak FuzionProof Research 157558: Lone Peak Arms 22 Creedmoor Threaded Rifle Barrel Sendero 18 in 8 Twist Pxt 5/8-24 Thread 2.5 Weight Carbon