The Rimfire Report: Which Way Rimfire Man? Ruger MK IV 22/45 vs. SIG P322

Luke C.
by Luke C.

Hello and welcome back to another edition of The Rimfire Report! This ongoing series, as always, is focused entirely on rimfire firearms and discussions around rimfire topics. Recently we took a look at one of SIG’s tricked-out P322 pistols. Most of you who keep close tabs on the blog will no doubt know that I absolutely loved my SIG Sauer P322 and wound up putting about 20,000 rounds through the pistol without issue in the first year of owning it. The previously mentioned P322 COMP version of the pistol brought the P322 platform back up on my radar specifically because it’s directly marketing itself as something that is more “competition-oriented.” While we’re going to settle out which one is the better competition pistol overall in a later article, this week, I figured we could take a closer look at what makes both the P322 and the Ruger MK IV 22/45 great first choices for a rimfire 22LR pistol.

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The Rimfire Report: Which Way Rimfire Man? Ruger MK IV 22/45 vs. SIG P322

Both the SIG Sauer P322 and Ruger MK IV 22/45 pistols are very reliable with the right ammunition. In addition to that, you can routinely find both pistols for a fairly affordable price with the Ruger being slightly more expensive in terms of both street price and MSRP. Generally, both pistols come with some of the same features for their base asking price including adjustable sights, and the ability to add optics to the pistol. However, this is where the similarities stop and where you’ll have to take into consideration each pistol’s core features to decide which one is ultimately for you… or if you’re just going to end up buying both.

Ruger MK IV Advantages and Disadvantages

The Ruger MK IV has a longstanding reputation and pedigree from the Ruger MK series of 22LR pistols. The handguns come in two different configurations but these days I’m finding that most people like the 22/45 configuration for its 1911-esque grip. The grip itself could play a major factor in your decision as the 1911-sized grip fits better in larger hands, but will also have the same drawbacks for those with smaller hands. Having to break your grip to remove the magazine or activate the slide stop isn’t impossible and can often be aided with aftermarket controls, but overall those with smaller hands will have a harder time operating the Ruger MK IV 22/45.

While mounting optics on the MK IV 22/45 is fairly easily done, the factory Picatinny rail mount leaves a lot to be desired in height over bore category if you’re going to do target shooting, and aftermarket mounts cost an arm and a leg, and are often only limited to a handful of smaller optic footprints. Holsters and lights are available for the 22/45 but once again they’re proprietary and in the case of lights, you’ll have to search for aftermarket options unless you happen to have an MK IV 22/45 tactical edition which features an included Picatinny rail.

The main strength of choosing the MK IV 22/45 platform from the get-go is the sheer amount of aftermarket parts and components you can order to either fix or modify your gun. My personal MK IV 22/45 is virtually all cannibalized out of various aftermarket parts that I’ve picked up throughout the years. With the 22/45 being my main rimfire Steel Challenge gun, I’m always happy to try new parts to see how they work and for many, this is part of the fun of owning a competition pistol – finding out what works best for you. That being said, the up-front cost of the MK IV 22/45 is going to be higher than the P322, and in addition, even though you have virtually any aftermarket part you want, they’ll cost you an arm and a leg.

SIG Sauer P322 Advantages and Disadvantages

Coming in at a bargain price and sporting a standard capacity of 20 rounds, the P322 has been one of my favorite rimfire releases of recent memory. Although the handgun has been reported to be unreliable and or just outright non-functional by many, I’ve found my two P322 pistols to be quite reliable with suppressed shooting once again gunking them up much more rapidly. Speaking of gunk, if you’re planning on shooting the P322 suppressed with an optic on it, be prepared to clean your optic, your hands, and probably even your face afterward – the P322 spits back quite a lot of gas which is kind of a shame since I think it’s the more “fun” of the two suppressor hosts.

The P322 doesn’t really shine as a competition or fast-shooting pistol. The flimsy feeling plastic trigger shoe and the reciprocating slide mean that you’ll have a tougher time staying accurate while shooting fast, and combining that with the P322’s extremely lightweight construction means you have a handgun that is much better suited to new shooters, and those having fun at the range than someone who is out to practice quick and accurate target transitions for competition.

Despite some of these drawbacks and a current lack of widespread aftermarket support, the P322 does have a lot going for it that the Ruger MK IV 22/45 does not. First of which is the standard magazine capacity of 20. Nothing is more boring at the range than reloading your gun and the 20-round or optional 25-round magazines mean you can keep the plinking going for longer. The dust cover rail, threaded barrel, optic mounting system, and ambidextrous controls are all standard features on the P322, and the optic that sits on the P322 will always sit much lower than on the MKIV – the P322’s slide was designed around optics whereas the MK IV was not.

Which One is Right for You?

Ultimately I honestly have to say you can’t go wrong with either handgun but I’d probably tip my hat to the MK IV 22/45 over the P322 7/10 times. The P322 serves as both a proper modern handgun trainer and a beginner’s plinker, although SIG’s track record of discontinuing products raises concerns about long-term support which might be scaring off the aftermarket crowd from really making the P322 a great addition to the rimfire pistol family. In addition to that, the P322 and its component parts aren’t built to last quite as long as a standard Ruger MK IV pistol.

On the other hand, the Ruger MK series offers extensive aftermarket support and even alloy grip frame options, with the Mark IV addressing previous reassembly issues and therefore making the handgun much easier to service. The Mark IV is held back by a design that is admittedly older than me and most people probably reading this, and the track record that Ruger has in the customer service department usually means that if your pistol isn’t working right, Ruger will take care of you so you’re back up and running as soon as possible.

Check Prices on Ruger Mark IV 22/45 Pistols

My solution would be to ultimately buy both but if you’re on a budget right now, start with the P322 first. The P322 can be a good in-row to 22LR pistols if you haven’t tried any yet, and since it shares virtually all of the same controls as a regular handgun you’ll have an easier time shooting it. If you’ve decided from there that you really want to get into rimfire pistol competition shooting, then you can jump from that to the MK IV 22/45 and keep your P322 as a fun weekend plinker! At least that’s what I would do! Let me know what your thoughts are and as always thanks for reading The Rimfire Report!

Check Prices on SIG Sauer P322 Pistols

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Luke C.
Luke C.

Reloader SCSA Competitor Certified Pilot Currently able to pass himself off as the second cousin twice removed of Joe Flanigan. Instagram:

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2 of 23 comments
  • Azntactical Azntactical on May 02, 2024

    Love my MKIV. Happy with my TX22 compact. Meh with my P322, she starts opening up groups after 200rds. Disgusted with my Walther P22Q. Emailed and called Walther and zero responses in 5 weeks. Fails to extract 50% of the time.

  • Dead Sirius Dead Sirius on May 03, 2024

    Luke must be new to rimfire. Outer Impact has a $55 mount which accommodates about two dozen optics. Or is $55 "an arm and a leg"?