Proof Research Tikka T3X 6mm GT Threaded Rifle Barrel Competition 26 in 7.5 Twist Pxt 5/8-24 Thread 7.9 Weight Silver. 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 Tikka T3X 6mm GT Threaded Rifle Barrel: Manufacturer: Proof Research Color: Silver Caliber: 6mm GT Barrel Length: 26 in Barrel Twist Rate: 1-7.5 Barrel Profile: Competition Firearms Threads Per Inch: 5/8x24 Gun Make: Tikka Gun Model: Tikka T3x Weight: 7.9 lb Gun Type: Rifle Package Contents: Proof Research Tikka T3X 6Gt Threaded Rifle Barrel What firearm models does the manufacturer say Proof Research Tikka T3X 6mm GT Threaded Rifle Barrel is compatible with? The manufacturer suggests that Proof Research Tikka T3X 6mm GT Threaded Rifle Barrel is compatible with Tikka T3xProof Research 155615: Tikka T3X 6mm GT Threaded Rifle Barrel Competition 26 in 7.5 Twist Pxt 5/8-24 Thread 7.9 Weight Silver