The Tactical Solutions Pac-Lite IV Upper (brand part number PLIV45TEMBRF) is a semi-auto, drop-in replacement barrel and upper assembly chambered in .22 LR and built to bolt onto your factory Ruger Mark IV or Mark IV 22/45 frame. Machined from lightweight aluminum with a stainless steel breech face and receiver, this 4.5-inch matte black upper trims weight off the front end while tightening accuracy and improving reliability over the stock unit. It installs onto your existing MK frame without a gunsmith, giving your rimfire pistol a lighter, faster-pointing feel. It is a proven upgrade for target shooters, plinkers, and anyone chasing tighter groups from their Mark IV.

Key Specifications

• Chambered in .22 LR, the same rimfire cartridge as the factory Mark IV platform it replaces.
• Barrel length is 4.5 inches, keeping the pistol short and quick to point for informal target work.
• Action type is semi-auto, matching the factory Mark IV operating system.
• Rifling twist rate is 1:16, matched to standard .22 LR bullet weights for consistent stabilization.
• Muzzle is threaded 1/2×28 and ships with a thread protector end cap installed.
• Crown is cut to an 11-degree target profile that protects the rifling and supports accuracy.
• Breech face and receiver are machined from stainless steel for long-term durability under repeated cycling.
• Complete upper weighs approximately 8.5 ounces, noticeably lighter than the factory unit.
• Top of the barrel is drilled and tapped for Pac-Lite scope bases, ready for a red dot or scope mount.

Frequently Asked Questions

What frames does this upper fit? It is built as a factory upper replacement for the Ruger Mark IV and Mark IV 22/45.

What caliber is it chambered in? It is chambered in .22 LR, matching the factory Mark IV platform.

Can I mount an optic on it? Yes, the barrel is drilled and tapped for Pac-Lite scope bases.

Buy the Tactical Solutions Pac-Lite IV Upper

Lighten up your Mark IV and pick up accuracy at the same time. Explore more Tactical Solutions upgrades in our gun accessories selection, and this upper ships fast from our Lubbock, Texas gun shop.