Pac-Lite IV Barrel fits Ruger MKIV and MKIV 22/45, Fluted, 4.5"The Tactical Solutions’ PAC-LITE IV pistol barrel is a lightweight and accurate .22 LR barrel and receiver for the Ruger® Mark IV™ or Mark IV 22/45™ pistol. The PAC-LITE IV upgrade represents what TacSol is known for in the .22LR aftermarket barrel industry; lightweight, highly accurate, and easy-to-install barrels. This barrel dramatically increases accuracy, performance, and reliability. The 1” outside diameter of the threaded barrel is designed to shoot and look great with or without attachment of a suppressor or compensator. Suppressors are easily attached by simply twisting them on the barrel’s threaded end. Hand-chambered for 22 LR, with a target crown and chromoly bore, the PAC-LITE replacement barrel upgrade is everything you could ask for in a pistol barrel.