I don’t think anyone was asking for a pint-sized 30-round semi-automatic .22 Magnum carbine, but that didn’t stop KelTec from bringing us the CMR30. Whether or not it’s ever been on your wish list, when you handle a CMR30, it’s the sort of gun that makes you say, “I kind of want that.” But since it’s a rimfire double-stack semi-auto, we have to ask a very important question: does it work?

Watch the video below for details, or scroll down to read the full transcript.

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Hey everybody, I am Chris Baker from LuckyGunner.com and today we’re going to be looking at the Kel-Tec CMR30; a .22 Magnum (aka .22 Winchester Magnum Rimfire or .22 WMR) semi-automatic carbine. We’ve got two of them here. One is the standard off-the-shelf version, and the other is a custom short-barreled carbine with all the fun stuff on it.

KelTec CMR30: Features and Specs

In 2011, Kel-Tec introduced the PMR30 – a blowback operated pistol chambered for .22 Magnum with a 30-round double-stack magazine. Five years later, they followed it up with a carbine version: the CMR30. The lower half of the carbine and pistol are very similar. They share a lot of the same parts, including the magazine.

When I first got to handle a CMR30, I was really blown away by how small and light it is. Just 3.8 pounds unloaded. 22.5 inches with the stock collapsed. It has pistol-style controls carried over from the PMR30. Ambidextrous manual safety levers. A bolt release on the left side only. A heel style magazine release. The charging handles are ambidextrous and non-reciprocating. So they do not move when you fire the gun.

The collapsible stock has five positions. To unlock it, you just press down on this lever here in front of the trigger guard. It does not lock into place when it’s fully collapsed, so you can just yank it out to whatever position you want.

The muzzle is threaded for a suppressor or other muzzle device. There’s an integral picatinny rail across the top of the receiver and a bottom rail forward of the trigger. It doesn’t have any built-in iron sights, but it does come from the factory with a set of Magpul folding sights.

The Short-Barreled CMR30

I have a real soft spot for ultra lightweight compact carbines, or what you might call PDWs. And like I said, the handling of this thing really grabbed my attention when I first saw it. But the 16-inch barrel is clearly out of place. It makes the gun front-heavy since the stock weighs almost nothing. It’s a real shame to have a gun that collapses down into this tiny package, but then stick a long barrel on it. The only reason KelTec was forced to make it this way is the legislative dumpster fire known as the National Firearms Act. The CMR30 is just begging to be cut down to a more appropriate length.

Now normally, I am not one to let 200 bucks and a little government paperwork get between me and a good time. However, in this case, the other issue holding me back was that this comes from KelTec – the home of gloriously unorthodox firearm concepts with tragically inconsistent execution. So I decided to just wait and see what other people thought of this gun first.

I kind of forgot about it for a few years, and then, in 2020, Dave Merrill wrote an article for Recoil Magazine called The Poor Man’s MP7. It was all about setting up a short barreled CMR30 since HK is never going to actually give us a civilian-legal MP7.

I saw that and thought, “Great idea, Dave. But I think I would set that up a little differently.”

So I did. Which means I ignored all the warnings about spotty reliability from just about every CMR30 owner on the internet, including Dave Merrill.

But more on that later. First, let’s look at our CMR30 SBR. It came from the factory with a handsome titanium cerakote finish on the upper. After getting my permission slip from the ATF, I had the barrel cut to 10 inches and re-threaded. That was done by Wood Brothers Gunsmithing here in Knoxville, TN. I highly recommend them if you’re in the area.

That brings the overall length down to just 16.5 inches with the stock collapsed and the unloaded weight drops to 3.3 pounds before accessories.

Dressing it Up

I’m not going to do anything with this gun that requires backup iron sights, so I took off the Magpul sights and I’ve just got a basic Sig Romeo 5 red dot on here.

This somewhat ridiculous tiger-print two-point sling is another stunning offering from Trunk Monkey Designs. I had to get a little creative with the sling attachment points. The CMR30 only has these two little loops in the back for a hook-style single-point sling. There are ways to add other sling attachment points, but I just decided to just use a set of Proctor Sling Loops. These are great because you can find a place on just about any gun to wrap a Proctor loop. The downside is that they’re not very quick to take on and off.

I see a lot of CMR30s with vertical foregrips attached. I don’t generally care for vertical foregrips unless it’s on a gun where the forend gets too hot to hang on to. But that’s not really an issue with the CMR30. I just added some rail covers from Ergo Grips to make the forend a more comfortable gripping surface.

This is my basic setup. But let’s say I wanted to ramp things up a little. Maybe I need to do nighttime guard duty at my chicken coop. In that case, I can throw this 3x Holosun magnifier behind the red dot and slap a Surefire Scout light on the front. Now I’m ready to ambush a nocturnal predator and the complete package fully loaded weighs only 5.7 pounds.

I’ve also replaced a few of the original parts on the CMR30. M*Carbo is one of the very few companies to support the CMR30 with aftermarket parts. Their safety levers have a wider shelf than the factory levers, making them a bit easier to manipulate. I also installed one of their stainless steel feed ramps to replace the plastic factory feed ramp.

M*Carbo also has an aftermarket trigger for the CMR30. I haven’t made that upgrade because I think the factory trigger is just fine. It’s not super crisp, but it breaks at about 3 pounds.

Does it Work?

So now the gun looks great. The handling is fantastic. I can store it just about anywhere. But how does it actually perform?

Well, like so many people before me have said of this gun, “it’s tons of fun… when it works.” The recoil is minimal. The 30-round capacity will put a grin on anybody’s face. The collapsible stock provides a surprisingly decent cheek weld. It’s just an enjoyable gun to shoot.

The CMR30 only runs with supersonic .22 Magnum ammo, which is not exactly quiet. Even suppressed, it’s nothing like shooting .22 LR. However, I think it’s softer shooting and quieter than a suppressed 9mm carbine. I’ve read some complaints about people getting excessive gas blowback in the face when shooting the CMR30 suppressed, but I have not found that to be the case at all. With a Silencerco Sparrow suppressor I hardly feel any of that gas.

This could even serve as the ideal packable general-purpose carbine if only it worked more often. But the reliability is just not there. It was okay at first, but after the first couple hundred rounds, I started getting multiple failures to fire and feed in every magazine.

After a lot of trial and error, I’ve got it running about 99% for the time being. This particular gun works best with CCI 40-grain MaxiMags – either the hollow point or the flat nose total metal jacket. Our unmodified CMR30 is not quite as picky about ammo, but it’s had its share of reliability issues as well. I don’t think the shorter barrel is the cause for the stoppages in the SBR – at least not the only cause.

Installing the M*Carbo feeding ramp improved reliability, especially after I polished it like they recommend. A lot of CMR30 owners report improved feeding with the M*Carbo magazine release, but in our case, it actually made things slightly worse.

It runs best when it’s clean and lubed. Unfortunately, it gets dirty very quickly when shooting it suppressed. I’ll give it a thorough cleaning after every 100 to 200 rounds. I haven’t shot it a whole lot without the suppressor. I would estimate it could go 400 to 500 unsuppressed rounds between cleanings.

Correctly loading the magazines is crucial with the CMR30. That is surprisingly difficult to do, and you can’t always tell that you’ve done it incorrectly. An aftermarket magazine loader is almost a necessity. I’ve been using this one from American Speedloaders. It’s helpful, but it’s still possible to end up with some rounds that are not lined up quite right.

In terms of accuracy, I’m sure the average .22 Magnum bolt action can out-shoot the CMR30. But I think it’s more than accurate enough for practical use. With CCI MaxiMags, I can consistently shoot 1-inch or smaller five-round groups from the bench at 50 yards. Cutting the barrel did not seem to hurt accuracy. Our SBR actually shoots slightly better groups than the unmodified carbine.

.22 Magnum Ballistics

Velocity does drop with the shorter barrel, but not as much as you might think. On average, velocity was 8% higher with the 16-inch barrel versus the 10-inch. Velocity dropped 25% going from the 10-inch to a pistol-length barrel.

So a 10-inch barrel does not quite take full advantage of everything that .22 magnum is capable of, but it’s still doing magnum things. Pushing a 40-grain bullet to 1700 feet per second is far beyond what .22 LR is capable of. In fact, that is the same bullet weight and velocity of an FN 5.7x28mm Speer Gold Dot when fired from a pistol.

That might sound like kind of a random comparison, but it’s actually a little hint of things to come. We are, right now, working on some ballistic gelatin testing to compare 5.7×28 to a few other cartridges. And for this batch of testing, in a first for Lucky Gunner, we are using genuine, organic-based FBI-spec ordnance gelatin blocks. Be on the lookout for those results later this year.

So, without giving away any spoilers from that project, the performance of .22 Magnum out of a 10-inch barrel is not bad at all for a low-recoil ultra compact carbine.

[Note: Check out our ballistic gel test results with 2-inch and 4.3-inch barrels for an idea of what .22 Magnum can do at lower velocities]

Conclusions

Unfortunately, the CMR30 is just not dependable enough to rely on for emergency life-saving purposes. There are several reliable pistol caliber carbines on the market that are much better suited for self-defense. However, I have made good use of this CMR30 as a pest control device. A couple of months ago, I used it to take out a mange-infested fox that had murdered some of our chickens the previous day. A single round at 70 yards was enough to incapacitate it and a second round finished it off.

The more time I spend with .22 Magnum, the more I appreciate it. I don’t think it gets nearly enough respect. It’s much more powerful than .22 LR and more accurate than the typical handgun cartridge. I wish the CMR30 was not the only PDW-type firearm chambered for .22 Magnum. But it’s a rimfire cartridge and that presents some unique design challenges. Smith & Wesson’s new .22 Magnum pistol looks promising. Maybe they’ll do a carbine version of that someday.

Until then, the CMR30 is an enjoyable gun if you’re willing to deal with some quirks. Hope you guys enjoyed this review. If so, be sure to subscribe to our channel and get some ammo from us with lightning fast shipping at LuckyGunner.com.