SIG P322 Handgun – The Most Reliable Rimfire Ever Made?

U.S.A. -( When I first received the invitation from SIG to attend the unveiling of the new SIG P322 pistol, I had fairly low expectations. Not because SIG doesn’t make great guns, but for two inherent issues with most semi-automatic rimfire pistols: they feel cheap, and they’re unreliable.

The SIG P322 is irrefutably neither of these things. And while that’s more than enough reason for a shooter to pick one up, there’s a hell of a lot more behind the new SIG pistol than just solid construction and excellent reliability.

The new SIG P322 is a very capable little handgun, that just runs and runs, even with a suppressor attached. IMG Jim Grant

SIG P322 .22LR Pistol

Despite its appearance, the new SIG P322 is a single-action only, semi-automatic, magazine-fed handgun chambered in .22lr. At first glance, you’d be forgiven for assuming the little pistol’s magazine capacity was limited to something like ten rounds. What’s incredible is that the new SIG features a new polymer 20-round magazine, with optional extended 25-round versions available now.

The SIG’s slide is made from anodized aluminum, and the method of operation for the pistol is simply direct blowback – which is true for basically every rimfire handgun on the market today. What’s unique about the design is that despite being a hammer-fired, single-action only pistol, the P322 looks like a striker-fired gun. This is because the hammer is actually shrouded not totally unlike old detective .38 revolvers back in the 1950s.

P322 Blue
The P322 looks hammerless, but its hammer is actually hidden inside the slide. IMG Jim Grant

As a blowback-operated pistol, the SIG features a fixed, 4-inch barrel that comes from the factory with an obfuscated threaded muzzle –  not unlike the GSG 1911 pistol. For the uninitiated, this means that the threaded portion of the barrel is covered with a smooth nut that resides underneath the slide itself. This way the gun retains a more classic look by not featuring a protruding threaded barrel. However, this nut features two slab cuts for tightening/loosening with a wrench and an extension that is threaded to the industry standard 1/2×28, so shooters can attach whatever suppressor they desire like this Innovative Arms SlingShot TI provided by SilencerShop.

P322 Suppressor
In testing, the P322 made a great suppressor host that was both quiet and very reliable like with this Innovative Arms SlingShot TI suppressor from SilencerShop. IMG Jim Grant

On the other end of the barrel, the chamber incorporates fluting just like HK uses on their G3 rifles and MP5 submachine guns. While many shooters bemoan this on centerfire guns as it tends to beat up brass in exchange for more reliable operation, this is a non-issue for rimfire ammo as nobody in their right minds would ever attempt to reload it.


Since the gun is single action only, it features a frame safety similar in function and placement to those found on a 1911 handgun. Unlike a 1911, the P322’s controls are fully ambidextrous. This includes both the serrated triangular magazine release button, as well as the slide release. Both of these appear to be made of stamped steel with a semi-gloss black finish, while the trigger is a more matte finish giving better tactile control – somewhat superfluous on a .22lr, but still a nice touch.

P322 in-hand
The P322 sits low and tight in a shooter’s hand, making it feel like a natural extension. IMG Jim Grant

Another great user-friendly feature is the P322’s inclusion of two different interchangeable triggers. This includes a more performance-style flat-faced trigger favored by top shooters, as well as a traditional curved one. I imagine most shooters will opt for the flat face, but as someone who learned to shoot handguns on Massachusettes-compliant ten-pound triggers, I find the curved trigger gives better leverage and faster shots.  Though shooters certainly won’t need that extra leverage, as the P322’s trigger breaks between four and six pounds, with a short reset/travel and a crisp break.

The frame itself also lends itself to fast shooting, with a grip that (in terms of thickness) feels somewhere between a P320 and a P365. Meaning that shooters of virtually all shapes and sizes will find the grip comfortable. Especially with its low bore axis combined with the trigger undercut and high backstrap; the gun just melds into the shooting hand making it feel like a natural extension of the shooter’s hand.

P322 Grip
The pistol’s grip features molded stippling, which feels great. IMG Jim Grant

Additionally, the frame features molded stippling on all sides, with “frames” of smooth polymer to accent them. This pattern appears to be identical to the one found on both the P320 as well as the P365 pistol. For shooters unfamiliar with either, the pattern offers omnidirectional traction without being so coarse that it would destroy holsters or the shooter’s hands.

Remarkable Magazine

Many companies have sought to challenge the magazine capacity limitations of .22lr with varying degrees of success. Some, like Kel-Tec’s CP33, did an admirable job allowing for incredibly capacious magazines – but with their own shortcomings as well. With that last example from Kel-Tec, the magazines were difficult to properly load. And due to the “quad-stack’ nature of them, suffered from a tremendous amount of cumulative friction. This in turn created feeding issues once the magazine became fouled up with was and lead from the notoriously dirty .22lr ammunition contained within.

The magazines employed by the SIG P322 are far simpler, yet still manage to hold an incredible 20 rounds. Basically, the P322 magazines function similarly a modern centerfire stagger-column magazine. The internal geometry of the magazines forces the rounds to stagger themselves alternating left and right with their rims.

P322 Magazine
Although conventional in appearance, the P322’s magazine holds an incredible 20 rounds! IMG Jim Grant

And unlike many other rimfire pistols, the magazines were very easy to load. Even when both Duncan and I attempted to induce a malfunction by folding the follower assist down past the necessary point and allowing rounds to fall into the magazine, the design seemed to sure them up nearly every time. Only when I pulled the follower to the bottom and dropped rounds in did the magazine seem to struggle. But even then, I was able to fix the issue by holding down the follower and giving the magazine a few shakes.

Lastly, SIG is immediately offering extended versions of these magazines with a 25-round capacity, and the gun ships with two 20-round magazines in the box. The P322 also includes a magazine loading tool, but after loading more than 30 magazines during the event, I can attest that this little tool wasn’t necessary for me at all. MSRP on spare magazines wasn’t concrete but is expected to be between $30-$40. Pretty standard for SIG firearms or any firearm utilizing a proprietary magazine.

P322 Sights

At first glance, the P322’s sights appear to be pretty standard fare for a modern combat handgun.  They feature a black serrated notch rear sight with green fiber-optic inserts adjustable for both windage and elevation and a fixed front sight post with the same color fiber-optic insert. But they actually have an interesting quirk – the windage and elevation adjustment screws are both located on the side of the rear sight.

P322 Front Sight
The SIG features green fiber optic front and rear sights. IMG Jim Grant

More interesting than that, is the fact that it comes from the factory with an optic mounting plate for a micro red dot like the SIG Romeo 1, or the Shield RMSC. While many centerfire handguns come with an RMR mount or something similar, historically mounting an optic to the slide of a rimfire pistol has been seen as impossible because of the relatively low energy of the round. Meaning, that adding weight to the slide could slow its movement enough to cause malfunctions. But this wasn’t the case at all with the new P322 when the gun was run with the lightweight SIG Romeo 1 sight. That said, I’ll be personally testing the gun with the heavier Shield RMSx red dot as soon as I get one in hand.

This fact alone tells you exactly what SIG had in mind when they designed the P322 – a range plinker that can serve double duty as a competition pistol. And that facet of the design I can personally attest to. At the P322 unveiling event in Orlando, Florida, a handful of shooters including fellow editor Duncan and myself had a chance to run the P322 through a series of rimfire steel challenge stages.  At every distance we attempted, the little gun was able to rapidly and accurately land hits on steel targets.

SIG Performance

And that brings me to the most impressive aspect of the new P322: reliability.

In my somewhat limited time with the P322, I personally fired around 700 rounds of CCI ammo through the gun as it ships from the factory – I also fired 200 rounds through a different P322 with a SIG suppressor attached. In both instances, neither gun ever encountered a failure to eject or failure to feed. In fact, the only issue encountered the entire day across dozens of pistols firing thousands of rounds, was a handful of failures to detonate.

And every one of these failures that I personally witnessed, was due to either a lack of primer or uneven distribution of said priming substance. (On one of the rounds that failed to detonate, it was loaded into two different guns multiple times and none of them could detonate it. This heavily suggests a lack of primer.

P322 Ammo
Throughout the entire review, the P322 never encountered a single mechanical malfunction. IMG Jim Grant

But let me reiterate and sum up those last few paragraphs. I fired an auto-loading rimfire handgun 700 times without a mechanical malfunction. If that doesn’t make you immediately sit up in your chair and either call me a liar or make you want to buy one of these guns, nothing will. As someone who has owned their fair share of .22 pistols, I can tell you from exhaustive experience, that most suffer a stovepipe within 50 rounds consistently. In fact, prior to this event, I had never seen a rimfire pistol capable of flawless operation beyond 200 rounds with the possible exception of my personal Ruger MKIII – and that was using Eley ammo and an immaculately clean gun.

My experience with the SIG was on a dusty, sandy range in the rain, on an already dirty gun – with any other gun, I would call that miraculous.

SIG P322 Verdict

Bottom line, is the SIG P322 worth a buy?

Abso-freaking-lutely yes. The P322 ships with two mags, a threaded barrel, two triggers, and an optic cut. That is an already impressive package but add to that the fact that the gun is literally peerless in terms of reliability and you have a recipe for total market dominance. What’s even better is that the gun has a MAP of $399 – which likely means shooters will see them sell for around $450-$500 initially, but then drop down in price once supply catches up with demand.

SIG Woods2
The new SIG P322 has quickly become the author’s new go-to suppressor host. IMG Jim Grant

And given the incredible reliability, excellent ergonomics, capacious magazines, and the fact that the firearm ships from the factory ready for both a suppressor and an optic for less than the cost of many of SIG’s competitors, I believe the P322 will become the 10/22 of handguns. The go-to recommended first handgun for new shooters that combines user-friendliness and affordability with inexpensive ammo.

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About Jim Grant

Jim is one of the elite editors for, who in addition to his mastery of prose, can wield a camera with expert finesse. He loves anything and everything guns but holds firearms from the Cold War in a special place in his heart.

When he’s not reviewing guns or shooting for fun and competition, Jim can be found hiking and hunting with his wife Kimberly, and their dog Peanut in the South Carolina low country.

Jim Grant

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