TACSOL Pac-Lite IV 4.5" Gray Barrel for Ruger MKIV 22LR

The TACSOL Pac-Lite IV 4.5" barrel for Ruger MKIV 22LR is a drop-in upper assembly that transforms your rimfire pistol into a finely balanced, accurate shooter without a trip to the gunsmith. This upgrade swaps out your factory upper for a lightweight aluminum receiver and barrel combination that noticeably improves handling and sight-in performance. Whether you're zeroing at 25 yards or pushing shots downrange on steel, the Pac-Lite IV cuts weight while tightening your groups—exactly what .22 LR shooters who care about their platform want.

Installation is straightforward: field-strip your MKIV, remove the factory upper, and drop the Pac-Lite IV into place. No special tools, no guesswork. The gun metal gray finish gives it a clean, purposeful look that complements both vintage and modern Ruger builds. The barrel features a 1:16 rate of twist optimized for standard and high-velocity .22 ammunition, a stainless steel breech face for reliability, and an 11-degree target crown to preserve bullet runout. Threading is 1/2" x 28, a common suppressor mount pattern if you want to run it quiet.

The 4.5" length strikes a balance—short enough for natural handling, long enough to wring velocity from rimfire loads. Pre-drilled and tapped receiver makes scope mounting intuitive; a thread protector (end cap) is included, so you're ready to shoot out of the box. Total weight sits at 8.5 ounces, a significant reduction from factory that makes a real difference in how the gun feels in your hand during extended range sessions or casual plinking.

Key Features

• Lightweight aluminum barrel and receiver reduces weight without sacrificing rigidity
• Stainless steel breech face for reliable feeding and extraction
• 11-degree target crown preserves bullet alignment and accuracy
• 1/2" x 28 threading accommodates standard rimfire suppressors and muzzle devices
• Pre-drilled and tapped for Pac-Lite scope bases—no gunsmithing required
• 1:16 twist rate handles standard and high-velocity .22 LR ammunition
• Thread protector included; ready to install and shoot

Specifications

Frequently Asked Questions

Does the Pac-Lite IV fit my Ruger MKIV?

Yes—the Pac-Lite IV is designed as a drop-in replacement upper for the Ruger MKIV and MKIV 22/45 frames. Installation requires only field-stripping; no gunsmithing needed.

Can I use a suppressor with the Pac-Lite IV?

The barrel is threaded 1/2" x 28, which is the standard suppressor mount for rimfire pistols. You can attach any suppressor or muzzle device with that threading.

What's included in the box?

The barrel assembly comes with a thread protector (end cap) installed, so you're ready to mount and shoot right away.

How much lighter is the Pac-Lite IV than factory?

The Pac-Lite IV weighs 8.5 ounces total, providing a noticeable reduction in overall upper weight compared to the factory upper, which improves handling and balance during shooting.