Proof Research Terminus Zeus 7mm PRC Threaded Rifle Barrel Sendero 20 in 8 Twist Pxt 5/8-24 Thread 2.10 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 Terminus Zeus 7mm PRC Threaded Rifle Barrel: Manufacturer: Proof Research Color: Carbon Caliber: 7mm PRC Projectile Caliber: .284 Caliber Barrel Material: Stainless Steel Barrel Twist Rate: 1-8 Barrel Profile: Sendero Firearms Threads Per Inch: 5/8x24 Gun Make: Terminus Gun Model: Terminus Zeus Gun Type: Rifle Package Contents: Proof Research Terminus Zeus 7Prc Threaded Rifle Barrel What firearm models does the manufacturer say Proof Research Terminus Zeus 7mm PRC Threaded Rifle Barrel is compatible with? The manufacturer says that Proof Research Terminus Zeus 7mm PRC Threaded Rifle Barrel is compatible with Terminus ZeusProof Research 156698: Terminus Zeus 7mm PRC Threaded Rifle Barrel Sendero 20 in 8 Twist Pxt 5/8-24 Thread 2.10 Weight Carbon