The Ruger Mark IV 22/45 White is a .22 LR pistol with a 4.4-inch threaded bull barrel and two 10-round magazines (Ruger part no. 40190-WHITE). Ruger builds the 22/45 on a precision-molded polymer grip frame with checkered, 1911-style grip panels, so it feels familiar to a 1911 shooter while running on inexpensive rimfire ammunition. Its one-button takedown lets the barrel-receiver assembly tilt up and off the grip frame without tools for chamber-to-muzzle cleaning. The 1/2-28 threaded muzzle comes with a thread protector, and a factory-installed Picatinny rail is ready for a red dot or scope. It is a natural fit for target practice, rimfire matches and teaching new shooters.

Key Specifications

• The chambering is .22 LR, an inexpensive rimfire for high-volume practice.
• Capacity is 10+1, and two 10-round magazines are included.
• The barrel is a 4.40-inch cold hammer-forged threaded bull barrel, heavy enough to steady the sight picture.
• The muzzle is threaded 1/2-28 and comes with a thread protector for popular muzzle accessories.
• Field stripping uses Ruger’s one-button takedown, which needs no tools.
• Sights are an adjustable rear and fixed front, with a factory-installed Picatinny rail for optics.
• The ambidextrous manual safety can be converted to left-side only with the included washer.

Frequently Asked Questions

Can I mount a red dot on this pistol? Yes. A Picatinny rail is installed at the factory, so a red dot or rimfire scope mounts directly to it.

What thread pitch is the barrel? The bull barrel is threaded 1/2-28, and it ships with a thread protector.

Will it fire with the magazine removed? No. The Mark IV has a magazine disconnect that prevents discharge when the magazine has been removed.

Buy the Ruger Mark IV 22/45 .22 LR Pistol, 4.4-Inch Threaded Bull Barrel, White

The 22/45 gives a 1911 shooter familiar grip panels in a pistol that is cheap to feed, and the threaded bull barrel and optic rail leave plenty of room to build on it. Order it from our Lubbock, Texas gun shop for fast, insured shipping to your FFL, and see more semi-auto handguns while you are here.