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Toby Obermeit, lead design engineer at Kel-Tec, holds a PMR-30 magazine. That magazine holds 30 .22WMR cartridges.  The design is very popular, with Kel-Tec shipping 500 of the pistols each week. I talked to Toby at the SHOT Show. He and Kel-Tec recently obtained a patent on a new magazine design that would create an even larger capacity for the .22LR cartridge. It would fit in a pistol grip, with a preliminary capacity of 33 rounds . . .

Toby said that Kel-Tec CNC has been granted the patent just a few weeks ago. It is specifically aimed at the .22LR. The one pictured in the patent drawings holds 33 .22LR cartridges, but would likely fit in a regular pistol grip. The patent is a departure from Kel-Tec’s more common practice. Kel-Tec has generally followed the strategy of getting product to market, rather than filing for patents.

Here is the abstract from the patent from uspto.cov:

 Abstract from the patent:

Double stack magazines have a tubular body defining an elongated passage and a lower and upper end, a floor plate element connected to the lower end, an elongated separator element within the passage, a follower defining an aperture receiving the separator element and movable within the elongated passage, a spring within the passage having a first end contacting the floor plate, and having an opposed second end contacting and biasing the follower toward the upper end of the body. The separator may be a rod spaced apart from the body surfaces. The spring may be spaced apart from the separator element. The spring may be a coil spring having multiple winds, each encompassing the separator element. The separator element may be medially located in the body. The separator element may be positioned to define first and second stack passages between the left and right side walls and the separator element.

It makes sense to me, in that the rod keeps the two columns of rimed cartridges separate, while using only a single spring system. Knowing Kel-Tec and Toby, I assume that it was prototyped with a 3D printer.

Toby made no promises as to when a product might result from this patent. He said that it would be at least a year in the future.

I have often thought that there was a lot of space inside .22LR pistol grips that wasn’t being utilized effectively. A 30+ shot full-sized .22LR handgun with a 5-inch barrel, threaded for a suppressor, and weighing about a pound, would be a very nice backpacking and general field or “kit” gun. A simple blowback design would allow for multiple barrel lengths and configurations.

I’d like to see arrangements for an optical sight. A small reflex sight would work nicely. A fixed barreled .22 pistol with an optical sight might be usable for small game to 60 yards.

©2015 by Dean Weingarten: Permission to share is granted when this notice is included.
Link to Gun Watch

[Jeremy S. edit: The PMR-30 magazines are pretty novel, themselves!]

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  1. I hope this can be generalized to other rimmed cartidges. A double-stack semi-auto in .357 Magnum would be awesome. A Sub-2000 chambered in .357 Magnum with such a magazine would make all other pistol caliber carbines obsolete overnight (.357 Magnum out of 16″ barrel is basically .30 Carbine ballistics).

    • It would make more sense if they just made PCCs in 10mm. Why try to pound a square peg into a round hole?

    • .357 is nice – however it is rimmed. I would opt for a 10mm:

      158gr — 1485ft/s — 774 ft·lbf

      155gr — 1,500 ft/s — 775 ft·lbf

      They are basically on equal ground.

      • Not sure if you caught my MechTech CCU review ( but you can get way more than that out of a 10mm carbine. Plus the option to run heavier bullets like 220 grain hard cast is pretty slick.

        But there are still some good, rimmed cartridges out there that make a lot of sense to run through a semi-automatic rifle with a double-stack magazine, and Kel-Tec has some great magazine designs for doing just this quite effectively (see that link I put at the end of the article above). From the large end like 7.62x54R to the small end just like .22 LR mentioned here, .22 WMR, .17 HMR and the new .17 WSM, .500 S&W, and whatever else…

        • If Kel-tec could apply this technology to making (This is just me hoping) a 7.62x54r RFB with a 15 or 20 round magazine, my life would be complete! Of course, you would have to clean it often because of corrosive ammo, but I feel the price of surplus is worth it!

      • Yes, and this mag design should completely solve the problem with the rim, hence my comment.

        Your comparison is for handguns. One neat thing about .357 Magnum (and .44, .45 LC and other revolver cartridges) is that they gain significantly more velocity in longer barrels, with 16-18″ being the sweet spot – more so than any semi-auto cartridge. It’s probably because they were all originally designed to do double duty in revolvers and lever actions.

        Either way, while e.g. both 9x19mm and 10mm gain something like 200 fps of velocity going from a 5″ barrel to a 16″ one, .357 Magnum gains 400-500 fps. Since energy is velocity squared, this actually translates to a fairly big difference. A typical 10mm load out of a 16″ carbine will be in the ballpark of 700-800 ft lbs at the muzzle. A typical .357 load out of the same, around 1200 ft lbs. And .357 will stay faster further away due to its smaller diameter and hence better BC. For comparison, M1 Carbine had around 950 ft lbs at muzzle.

        But that’s regular loads. For hot ones, the difference can be even more drastic. If you take something like Buffalo Bore and compare… BB 10mm 180 grain hard cast goes at 1600 fps out of 16″ barrel, yielding almost 1000 ft lbs (note, still less than a common .357 load). On the other hand, BB .357 Magnum 180 grain hard cast does over 1800 fps, for 1300 ft lbs.

        At this point we’re already getting into rifle energies – 1300 ft lbs, coincidentally, is the muzzle energy of a 62 grain 5.56 round out of a 20 inch barrel. But hey, it gets better. Buffalo Bore also makes hot loads that are lighter and go even faster. In particular, they have a 158gr JHP load that does 2150 fps out of 16″ barrel, and a 125gr load that does 2300 fps. This translates to just over 1600 ft lbs at the muzzle for 158gr, and slightly exceeds the standard 7.62×39 load fired out of a 16″ barrel (i.e. AK-47)!

        Do you see now why I really want a 16″ .357 carbine? 🙂

      • Bullet design being equivalent, in your example the .357 will penetrate much deeper than the 10mm. Which can be a good thing depending on the target. Higher SD means deeper penetration. For thin stuff, the .357 stoked with 125 grain bonded core bullets is the ticket, and that’s really the better comparison to the 10mm 155.

        Personally, I prefer the 10mm in a repeater though, since it’s likely to be more reliable.

    • A double stack magazine for Ruger’s 77/357 would be awesome! Given the amazing range of loading a for .357, you’d damn near have the perfect survival rifle.

      The only thing that keeps me from buying one of those is the low capacity. Why not just stick with my lever gun and it’s 9+1?

  2. I never understood the fascination with continuing to use rimed cartridges. They make life par more difficult that they are worth and can be easily replaced with more modern designs. (You can even make a “rimfire” without the rim given the right manufacturing process.)

    • Despite a spike in pricing of late, there’s no way to make a centerfire cartridge competitive on cost with .22 LR. As we will continue to use .22 LR for all sorts of reasons well into the conceivable future, the entry to the market of reliable, double-stacks mags is very welcome. It’s annoying to need a 16″-long banana magazine just to hold 25 rounds of freakin’ .22. The PMR-30 mags are awesome and it’ll be great to see that sort of design entering the .22 LR market. My #1 hope is that Kel-Tec actually manufactures the magazines as aftermarket replacements for lots of existing .22 LR firearms, like the 10/22 and Rem 597 and some of the tacticool .22 ARs like the M&P-15-22, etc etc… There are even some pistols with normal-sized magazine wells but single-stack .22 LR magazines with extra material on either side to fill the mag well (CZ Kadet, plus .22 conversions for Glock, Sig, 1911, etc) that could at least double capacity by going double stack and using all of the available length as well (lots of them are intentionally blocked to 10 rounds even if they had room to hold more).

      • “My #1 hope is that Kel-Tec actually manufactures the magazines as aftermarket replacements for lots of existing .22 LR firearms…”

        My #1 hope is that Kel-Tec recognizes their limitations as a manufacturer and licenses the patent to other firearm companies who can actually ship products in larger-than-novelty quantities.

        • Licensing would be their best bet. They aren’t willing to do what is necessary to meet demand, and they have some cool, innovative designs.

    • I went plinking this weekend with my scoped Marlin 795. I shot 150 rounds and spent less than $15. Even firing 7.62×39 or 5.45×39 I can’t match that price. .22lr is still a lot of fun to take shooting and affordable when you can find it.

      • I was referring, primarily, to rimmed .44 magnum and .357 magnum cartridges. I would be that you can make a .22LR copy without the rim for a fairly low cost.

      • “22lr is still a lot of fun to take shooting and affordable when you can find it.”

        The “when you can find it” part IS the problem!
        If I could find 150 rounds of decent .22LR for under $15, I’d be very happy!

    • The problem is that they cannot be easily replaced. Sure, designing a replacement cartridge that does just as well or better and doesn’t have a rim isn’t hard. But getting it adopted widely, which is coincidentally what’s also necessary to fully reap the benefit of scale and hence make it cheap, is very hard.

    • Rimmed cartridges make headspacing a chamber in situations like a revolver or other situations pud-easy.

      Sure, you can headspace off the case mouth, and that works… right up until you want to use loads so hot that unless you roll crimp your case mouth into a cannelure in the bullet, the bullets on unfired cartridges start to walk out of the case mouth. If you’re headspacing off the case mouth, how are you going to do a roll crimp?

      OK, another scenario. The S&W Model 52 target pistol. They use flush-seated wadcutter pills. There’s a slight crimp on the case mouth. How are you going to headspace that cartridge unless you have a rim or a belt? That’s why they went with a .38 case.

      The .22LR has the crimp issue. Look very closely at the cartridge and you can see a slight crimp of the case mouth into the bullet base.

      When you’re looking at cartridge designs, you have to think about the whole picture. There are some good reasons for a rim on a cartridge. When you’re using a bullet where you can get away with a taper crimp, the rim on a case becomes a non-issue or possibly a bother; you can headspace off the case mouth.

      When you need a roll crimp, you need a roll crimp, and then you’re going to need some other way to headspace the cartridge: a shoulder, a belt or a rim.

  3. That’s Nice.

    Can someone please tell Mr. Obermeit to make us an all steel slide. Polymer frame? Fine. Please add some more steel up there on the top – I really don’t mind paying more.

    • +1

      & Make the Barrel strong enough to support itself and a suppressor.

      Then, make one that does the same thing for .40 S&W.

      • I’ve often thought that Kel-Tec would do wonderfully to license/produce traditional versions of their products. I’d love me a Sub-2000 made from something a little less… plasticky.

  4. A vaporware magazine for vaporware ammunition.


    /jk luv ya kel tec, dont kick me out of your booth….

  5. I think I’d be more likely to buy a pmr in 22lr than the 22wm. Just pure cost reason and the fact that I would consider both a toy. Not real keen on using 22wm or lr for anything serious even hiking defense.

  6. Right now the Keltec magazines are not going to be holding any .22LR or .22WMR. Heck, I have not seen any .22LR or .22 WMR in stores since Thanksgiving.

    • Just bought another 5,000 rounds of CCI Mini-Mags to add to my existing 7,000-round stash.

      Admit it to yourself, the price on .22 is not going down any further from where it’s already at. At under 10 cents / round online, it’s still way cheaper than anything else. Get it at that price before the next spike in 2016.

  7. I find it interesting that Keltec patents this and not their P11 or tiny 32’s or 380’s. Which SCCY and especially Ruger ripped off completely. I do see the IO Hellcat failed. Oh well…

    • Because a 30+ round double-stack magazine for rimfire ammunition is a novel and patentable device, whereas a pocket pistol is not?

    • Ruger took the P3AT and made it reliable like it should have been to begin with.

      George Kellgren has good ideas with lots of potential but he isn’t very good at turning them into a well made and reliable end-product. His insistence on doing things on his own without outside help is holding his designs back.

  8. Kel Tec seems to be doing OK putting money in the bank and growing as private company. Something few other have done. My SU-16D, PF-9 and P-3AT are very reliable guns. They are accurate when I use laser sights. But at 72 that’s true with all guns.

    The high capacity 22 LR magazine would make a great pistol or rifle. A rifle like the SU-16D with the magazine in the hand grip would be a natural. A legal length firearm with a removable butt stock much like the Sub-2000 or SU-16 with fore grips that functions without the butt stock is also a natural kit gun.


    “One man with a gun can control 100 without one.” -Vladimir Lenin

  9. Do your research:
    There are stories of these Kel-Tec 22’s blowing up. I haven’t heard of anyone losing fingers or eye sight, but there are stories to be found. Add this to the Option of a threaded barrel for this gun and the note Kel-Tec adds about not recommending and voiding warranties with the use of a silencer. The silencer as per Kel-Tec creates for gas pressure that can blow open both the barrel and the gun cartridge.

    I did my research on another Kel-Tec Product, Their tactical shotgun with dual ammo chambers. It had flimsy parts that would sooner or later break, and said the gun could be fired in all positions. The gun can NOT be fired in all positions because some positions prevent shell ejection.

    I applaud Kel-Tec for seeking higher capacity guns, but please, go back to the drawing boards.

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