Smith & Wesson's High-Capacity M&P22 Magnum: Best .22WMR Pistol

This high-capacity, polymer-framed semiautomatic pistol could be the most versatile .22WMR sidearm ever devised.

July 31, 2024 By Joseph von Benedikt

Smith & Wesson’s new high-capacity .22 Magnum pistol is one of the most innovative handguns introduced in the last 12 months. It is sleek and lightweight, yet it packs an astonishing 30 cartridges in its magazine. Unlike most ultracapacity pistols, the M&P 22 Magnum does not have an awkwardly fat grip. On the contrary, thanks in part to the slender nature of the .22 Magnum (WMR) cartridge and in part to excellent grip frame engineering, the pistol has a slim, comfortable grip. Another unique feature is that although the M&P 22 Magnum looks like a striker-fired pistol, it actually features a single-action internal hammer. This enables it to have a better trigger than nearly any striker-fired pistol. Those features, however, are really just features. The engineering genius comes into play with the unique barrel system. The action is fundamentally a blowback type. However, it’s a delayed system—crucial to harnessing the zesty energy of the .22 WMR cartridge and converting it into a reliable operating system.

smith-wesson-m-p-22-magnum-pistol-02 — The M&P 22 Magnum pistol features a unique, delayed blowback action. What appears to be the barrel here is actually a fixed barrel shroud. The barrel reciprocates inside it. Good engineering kept the M&P 22 Magnum’s grip narrow and comfortable. Here, the magazine is partially out, showing the minimal grip walls and the maximized width of the magazine that enabled the pistol’s 30-round capacity. Note also that the magazine release is reversible for left-handed shooters.

Vital to this system is the shrouded barrel. What appears to be the barrel is actually a fixed shroud. The barrel proper is a slender affair housed inside that shroud. The delayed function is achieved via a port near the front of the barrel, which bleeds propellant gases off. These gases provide the rearward thrust needed to propel the barrel breech rearward within the shroud. This imparts a robust shove to the slide face, opening the slide and extracting and ejecting the fired case. The slide is then propelled forward as the recoil spring decompresses, picking up a fresh cartridge from the magazine and chambering it. Historically, semiautomatic .22 WMR firearms have always been problematic. As a result, revolvers and bolt-action rifles are far more common. Time will reveal whether the delayed blowback system of the M&P 22 Magnum overcomes those issues, but it’s good to know that the entire system was designed specifically for the cartridge. For whatever reason, the .22 WMR cartridge gained a cult-like following early on, and it has maintained that discipleship since its introduction in 1959. Possessing a pistol that holds a full 30 rounds of .22 WMR ammunition is a compelling temptation.

M&P22 Features

smith-wesson-m-p-22-magnum-pistol-03 — Smith & Wesson’s new full-size .22 Magnum pistol holds 30 rounds in the state-of-the-art polymer magazine, but the pistol weighs just 22 ounces. Two magazines come with each pistol.

In addition to the 30-round capacity and its unique operating system, the M&P 22 Magnum has a plethora of attractive features. For those with fading middle-aged eyesight (like me), or for those who simply prefer a red-dot optical sight atop their pistol, the M&P 22 Magnum comes optic-ready, with the slide machined to fit popular red-dot sights and a filler plate installed. The factory sights are good, too. The front is a nice yellow/green fiber-optic type, and the square-notch rear sight has antiglare striations. The pistol is configured with a Picatinny rail on the frame in front of the trigger guard, and it makes mounting a light/laser device easy. The fire controls are fully ambidextrous, with the exception of the magazine release—which is reversible, so southpaw shooters can set up their sidearm exactly as they wish. There’s a slide lock lever and a manual thumb safety lever on each side of the pistol. They are low in profile but feature slip-reducing striations that help make operation sure. Elegant directional grooves grace the rear of the slide. It’s slick-surfaced up front, so it will slide in and out of a holster without hang-up. What’s not slick is the grip. It has a really nice stippled texture that will provide a good nonslip grip whether your fist is wet with mud, blood, or sweat.

In addition to being slim, grippy, and comfy, the grip is nice and high under the rear of the slide, enabling a high, recoil-controlling grasp on the pistol. The rear of the trigger guard is undercut to match. Not that the M&P 22 Magnum has much discernible recoil, but for shooters who understand the benefits of a good high clench on their pistol, its grip configuration is a definite plus. A flat-faced trigger shoe with internal safety lever provides a distinct, clean feel beneath the trigger finger. Combined with the crisp single-action release of the internal hammer, it provides a very good feel, akin to that of a nice Model 1911 trigger. Two 30-round magazines come with each M&P 22 Magnum pistol. For those interested, the pistol will fire with the magazine removed. Disassembly for field cleaning and maintenance isn’t quite as easy as with most centerfire polymer-framed pistols, but it isn’t challenging. Simply remove the magazine, clear the chamber, rack the slide to cock the hammer, then press the slide rearward about 3/8 inch out of battery to align a half-moon cutout in the left side of the slide with the takedown pin. Use a small punch to press the protected tip of the takedown pin. Push it right through and out of the pistol. Release the slide and pull it forward off the frame. Lift the captive recoil spring and guide rod out of the slide assembly, then the barrel shroud and barrel. Pull the barrel out of the rear of the shroud and you’re done. Assemble in reverse order.

Shootability

smith-wesson-m-p-22-magnum-pistol-04 — The flat-faced trigger provides a distinct feel beneath the finger and helps enable consistent shooting. Note the low-profile magazine release. M&P 22 Magnum pistols are optic-ready. Just remove the filler plate and install your choice of red-dot sight.

Some types of ammunition are still hard to come by, as supply hasn’t quite caught up with demand post-COVID. But I was able to find two different .22 WMR loads to test through the M&P 22 Magnum. They were Federal’s blue-box Game-Shok 50-grain JHPs and Hornady’s Critical Defense 45-grain FTXs. Resting the M&P 22 Magnum over a sandbag, I fired three consecutive five-shot groups at 25 yards with each loading. Impact elevation was either right on or a tad low, depending on how you use handgun sights. I use the top flat of the front sight, so groups were an inch or two low for me, but if you aim by plastering the glowing fiber optic right on your target, elevation would be perfect. Horizontal point of impact was a couple inches left, but that’s easily solved by loosening the hex-head locking screw and drifting the sight slightly in its dovetail. Groups ran from less than an inch for the best—fired with the Hornady ammo—to about 1.75 inches. Accuracy honors went to the Hornady load, with an average of 1.15 inches, but both loads shot just fine for practical purposes—certainly within minute-of-fox vitals and probably even inside cottontail head-shot spec. Velocity from the 4.35-inch barrel was considerably less than from a .22 WMR rifle barrel, as expected. Still, the M&P 22 Magnum pushed 45-grain bullets about 100 fps faster than a .22 LR rifle pushes 40-grainers and a good 300 to 400 fps faster than a .22 LR pistol pushes 40-grain bullets. That’s an impressive step up in terminal performance. Reliability testing was interesting. It seemed that the long brass cases of the Federal ammo acted a bit rubbery, if that makes sense, as they entered the chamber at the angle presented by the magazine feed lips. About one in five cartridges would hang up slightly, half chambered, and needed a mild encouraging press on the rear of the slide to get them chambered. The nickel-plated Hornady cases, on the other hand, slid into the chamber as if greased. Presumably, the natural lubricity of the nickel provides a reliability benefit.

smith-wesson-m-p-22-magnum-pistol-05 — When the gun is field-stripped for maintenance, the barrel and shroud are clearly visible. A vent hole near the muzzle of the barrel activates the delayed blowback system.

I wish I’d had several other loads to test through the M&P 22 Magnum in order to give it a more thorough functioning test; however, I can surely attest to the pistol’s extremely shootable nature. It points wonderfully. The sights are easy to see and line up. The trigger is light and releases cleanly. Recoil is negligible. Trigger reset is short, crisp, and tactile. As for reloads, what reloads? You have 30 rounds on tap. I’ll go so far as to utilize the old saying about early Henry 1860 and Winchester ’73 rifles: You can load it on Sunday and shoot it all week. What’s the M&P 22 Magnum good for? Well, first, pure plinking fun. Yes, it’s more expensive to shoot than a .22 LR, but it’s also much cooler, what with the huge magazine capacity and the visibly greater on-impact results. More practically, the M&P 22 Magnum is a prime fur-trapping pistol (pun intended). It’s lightweight, accurate, easy to shoot precisely, and packs enough wallop to quickly dispatch foxes, beavers, coyotes, and even wolves and lynx with head shots. And you’ll never have to reload your pistol while trudging along on your snowshoes—you’d have to have a spectacular day indeed on the trapline to run through all 30 rounds. Some folks will also press the M&P 22 Magnum into service as a self-defense gun. And why not, particularly for recoil-sensitive shooters? You have nearly double the rounds in the magazine as the average full-size polymer-framed 9mm pistol. Terminal authority isn’t great, but when loaded with purpose-built .22 WMR ammo, such as the Hornady Critical Defense this particular pistol likes, it is nothing to sneeze at. Unlike some new pistol models, which don’t get adopted into various families of holsters until they’ve proved they have lasting power, the M&P 22 Magnum already boasts an impressive lineup of compatible holsters. Gunfighters Inc. alone offers four different types, ranging from concealable belt holsters to chest holsters and shoulder holsters. Craft Holsters has several models too, including a nice leather small-of-the-back holster and several concealable IWB and OWB hip holsters. Several other makers provide holsters appropriate for the M&P 22 Magnum, too.

There’s one other aspect of shooting the M&P 22 Magnum that’s worth mentioning: ammo cost. The online searches I did showed that most loads—when available—run from $14 to $23 per 50 rounds. That’s about on par with 9mm plinking ammo these days, so there’s no real “cheap rimfire” ammo cost advantage. However, the easy-to-shoot, easy-on-fur advantage is there. Plus, of course, that 30-round capacity benefit. Do you need an M&P 22 Magnum? That, of course, is entirely dependent on personal taste and tasks. If you run a serious trapline or want a very low-recoil, high-capacity sidearm for personal protection, you should strongly consider the M&P 22 Magnum. It’s a beautifully engineered, uniquely useful handgun that’s superbly built by one of the most respected manufacturers in the world.