Semi-automatic pistols chambered for the .22 WMR cartridge have been rare over the years, especially when compared to the ever-popular .22 LR rimfire models. This is most likely due to the mechanical challenges of building a pistol action that will operate reliably with the .22 WMR, which is more commonly known as .22 Magnum or .22 Mag. This long, slender, tapered and rimmed cartridge can be problematic when feeding from removable box magazines.
In January of 2023, at the annual SHOT Show held in Las Vegas, Nevada, Smith & Wesson announced the arrival of the company's first pistol chambered for the 5.7x28 mm bottleneck cartridge. Just a few months later the company announced that this same new M&P series pistol design would be available chambered for .22 Mag. Here are a few reasons why this is a unique rimfire pistol.
1. The Innovative TEMPO 2-Piece Barrel Design
The vast majority of semi-automatic handguns available today feature actions which are recoil-operated (tilting barrel) or blowback operated (fixed barrel). This M&P is unusual in that it is gas-operated using the two-piece, patented rotating TEMPO barrel system. A gas-ported and gas-checked inner barrel turns and shifts a short distance back and forth within a rounded outer barrel, or sleeve.
This M&P model is essentially the 5.7x28mm pistol chambered in .22 Mag.
The locked-breach TEMPO configuration offers two key advantages. First, it keeps all of the action's components locked in place until the bullet passes the inner barrel's gas port, which is near the muzzle. This works to reduce felt recoil and contributes to more consistent shot placement. Secondly, this barrel configuration makes the gun more reliable. In this case, the system is well suited to the shifts in levels of pressure common to shooting rimfire rifle cartridges, i.e the .22 Mag., from shorter semi-automatic pistol barrels. This is not the first semi-automatic pistol with a rotating barrel, but it is an innovative twist of the concept which works reliably and consistently.
The front sight is fitted with a bright green fiber optic.
2. Ammunition Capacity & Availability
One reason that polymer-framed, semi-automatic pistols have become so popular for sporting and self-defense applications is the ammunition capacity their double-stack magazines provide. Generally, these magazines hold somewhere between 15 to 18 rounds, depending on the caliber and pistol model.
The optics-ready slide cutout is sized for optics with a smaller Shield RMSc footprint like the Holosun EPS Carry optic shown here.
Because the .22 Mag. cartridge has such a slim profile, Smith & Wesson was able to develop a 30-round magazine to fit this M&P pistol for a total of 31-rounds on board with one in the chamber. In other words, about four magazines worth of ammo fit into the two magazines that ship with the gun.
External controls include an ambidextrous slide stop, reversible magazine release button and an ambidextrous thumb safety lever
In regards to .22 Mag. ammunition cost and availability, Smith & Wesson recognized that this caliber is a useful reduced-recoil option which fits neatly between the .22 LR and 5.7x28mm cartridges. Pistols chambered in .22 Mag. are more powerful than .22 LR handguns but not as powerful as 5.7x28mm. Ammunition for .22 Mag. pistols costs noticeably more than .22 LR while being less expensive than 5.7x28mm. The .22 Mag. ammunition currently available is not nearly as diverse or readily available as the ubiquitous .22 LR but it is still much more common and easy to find than the 5.7x28mm which is growing in popularity but still finding its footing in the U.S. market place.
3. Up-To-Date Pistol Features
Some of the other pistols in this caliber have been around for some time now with little in the way of updates to their features or designs. This M&P’s features are right in line with what customers expect from current production Smith and Wesson pistols. The gun arrives optics-ready with a slide cutout sized for smaller optics with a Shield RMSc footprint. It was just the right size to keep working with the top notch Holosun EPS Carry MRS optic, which was included in this revolver review. The EPS is a good fit for this pistol because of its compact size, durable housing, enclosed emitter and the sighting reticle which can be viewed as a small central dot, a ring, or both at the same time. It's an optic that can comfortably straddle both handgun hunting and defensive roles.
This pistol is simple to disassemble for routine cleaning.
The slide proved to be easy to cycle manually with less pressure required than a typical 9 mm. The trigger exhibited a light, clean take-up before breaking with 4 lbs. 11 oz. of trigger pull. The grip shape is a bit unusual in that it's relatively slim side-to-side but more elongated front-to-back in order to accommodate the .22 Mag. cartridge. In my somewhat smaller hands, I found the grip to be comfortably hand filling, there was plenty of room for all the shooting hand fingers, and the grip texturing was effective without being abrasive.
The full-size textured grip is hand filling and comfortable to use.
This M&P qualifies as a full-size pistol, which is 8.4" long, 5.9" high with a grip width of 1.13". It's a bit lighter for the duty size class with an unloaded weight of 22 oz. With an optic installed and 31 rounds of 45-gr. bulleted ammunition on board it tips the scales at 28 oz. The slim stainless steel slide features Smith & Wesson’s durable matte black Armornite nitride finish and rear cocking serrations. The factory installed sights consist of a green fiber-optic front and a drift-adjustable, serrated square-notch rear sight. Other features include a 2.25" 4-slot dust cover accessory rail, ambidextrous slide stop lever, a reversible magazine release button and an ambidextrous thumb-safety lever.
The magazines hold 30 rounds of ammunition for a total ammunition capacity of 31 shots with one in the chamber.
4. A Reliable & Accurate Rimfire (With the Right Ammunition)
In the course of working with a variety of revolvers and semi-automatic pistols chambered in .22 Mag., loads which fire jacketed bullets weighing 40 grains to 45 grains have generally produced the best results when fired from handgun barrels between 1" to 4.5" in length. With this in mind, the formal accuracy ammunition test set included loads in both of these bullet weights.
Ammunition for this pistol is available in a variety of jacketed bullet weights and styles.
However, Smith & Wesson states in their literature that the TEMPO barrel system allows its .22 Mag. pistol to cycle reliably with bullets as light as 30 grains. They provide a list of factory tested loads which includes 30-, 33- and 35-gr. rounds. But just for the purposes of being both contrary and cantankerous, I packed up a Hornady 25-gr. NTX Varmint Express load along with the rest of the test ammunition, just to see what would happen. I had other loads on hand in the prescribed bullet weight range in case it proved to be a poor fit.
Federal’s Punch load yielded the tightest 5-shot group of 1.56” at 25 yards.
Although rimfire pistols are notoriously ammunition sensitive, the M&P proved to be utterly reliable with all of the ammunition tested, including the 25-gr. load. There were no jams, failures to fire or to eject with any of the rounds fired. The only oddity that cropped up was that the last three rounds in the 30-round magazine would not feed into the pistol when using this particular lightweight Hornady round. All other loads tested fed until the magazines were completely empty. I haven't seen a gun and ammunition combination behave quite like this before, so let's chalk it up to that particular load just not being the best fit for this gun. After all, the bullet is lighter than those recommended by the manufacturer.
Some interesting performance points cropped up during formal, bench-rested five-shot group accuracy testing. Here are the results:
The Remington Magnum Rimfire and Hornady Varmint Express rifle rounds had lower velocities, which translated into reduced bullet energy. This is to be expected. But notice that the Federal Premium Punch Personal Defense pistol-specific load picked up speed for improved performance when fired from this pistol.
As for accuracy, if the five shot groups are between 3" to 3.5" when I'm pulling the trigger at this distance, then the gun, ammunition and the shooter are all working properly. Generally, my groups can tighten up by as much as 0.5" when using a micro red dot optic like the Holosun EPS. As it turned out, the largest groups, produced with the light-bulleted Hornady load, still averaged under 2.29" with the Remington load averaging 2.09". The heavy bullet Federal load, the only one to gain more velocity in this pistol, kept all groups under 2" for a 1.71" average. This is rock solid accuracy for a factory standard handgun.
5. A Useful .22 Mag. Pistol for Sporting or Low-Recoil Self Defensive
Smith & Wesson's M&P .22 Mag. pistol proved to be accurate, reliable and exceptionally comfortable to shoot. It also has the advantages that come with a modern, optics-ready full-size pistol that also sports a 30+1 ammunition capacity. After spending time with this gun at the shooting range, it has found a place on my favorite new guns of the year list.
The TEMPO 2-piece barrel system allows the pistol to self adjust for what are, in this caliber, significant changes in bullet weight and cartridge pressure levels contributing to a level of reliability not commonly found in rimfire pistols. Smith and Wesson makes the same recommendation for this pistol as I would: Run a few boxes of your intended ammunition through this gun before taking it into the field or staging it for self-defense. For sporting purposes, feel free to explore the bullet weights available. But I would say for those who choose to use a rimfire for personal protection, stick to the 40- or 45-gr. bullets with the loads configured specifically for handguns being the best option. This model has a suggested retail price of $649.
For more information, visit smith-wesson.com.
Manufacturer: Smith & Wesson
Model: M&P .22 Magnum (#13433)
Action: Gas Operated, Mechanically Delayed Blow Back, Semi-Automatic, Internal Hammer Fired
Caliber: .22 WMR (.22 Mag.)
Barrel: 4.35" Stainless Steel TEMPO 2-Piece, Matte Black Finish
Slide: Slim Profile Stainless Steel, Matte Black Armornite Nitride Finish
Sights: Fiber-Optic Front, Serrated Square-Notch Rear
Optics Ready: Yes, Shield RMSc Footprint
Frame: Textured Polymer
Overall Length: 8.4"
Weight: 22 oz., Unloaded
Capacity: 30+1 Rounds
Rifling: 6-Grooves, 1:10 RH Twist
Accessories: Foam Lined Carry Case, Two Magazines, Cable Lock, Owner's Manual
Optic: Holosun EPS Carry MRS (HE507K-GR X2), $376.46