The Firearm Blog

Inevitably, Kel-Tec's new .22 Magnum (WMR) chambered PMR-30 pistol will be compared to the FN Five-seveN pistol which fires the ballistically similar 5.7x28mm cartridge. If people are not saying it now, they will be soon saying that the .22 Magnum is the same as the 5.7x28mm. I used to say the same thing. It turns out that this is far from the truth.

Kel-Tec have stated [PDF Link] that a 40 grain .22 WMR round should reach a velocity of 1230 fps from the 4.3" barrel of their PMR-30 pistol. This works out to 134.40 ft/lbs of energy.

This is a significantly less than the FN Five-seveN USG (4.75" barrel), which can push a 40 grain bullet at 2009 fps. This works out to 358.57 ft/lbs! Nearly three times as powerful as the .22 WMR! ¹

This does not mean that the .22 WMR is not a good cartridge. It simply means that the 5.7mm is optimized to be fired from a pistol, rather than the slower burning .22 WMR loads which are designed to be fired from a rifle.

UPDATE: Added correct link to specs on Kel-Tec's website : http://www.kel-tec-cnc.com/downloads/SHOT2010_preview_keltec_PMR-30.pdf [PDF Link]

Kel-Tech have developed a new pistol which chambers the .22 Magnum (WMR) rimfire cartridge. The small size of the .22 WMR has allowed Kel-Tec to squeeze 30 rounds into the double-stacked magazine (a new original design), yet maintain a comfortable grip size.

The PMR-30 has a unique hybrid blow back / locked breech recoil system. In order to accommodate a wide range of ammunition, the pistol automatically adjusts between locked breach and blowback based on internal pressure. I look forward to seeing how this system works.

One problem with the .22 Magnum is that because it was designed as a rifle cartridge, the powder load is slow burning. This maintains high pressure in the barrel for a longer period of time. This high pressure can prevent extraction during recoil because the gas pushes out against the brass and presses it into the chamber wall. Shooting Log report that the PMR-30 has a fluted chamber to prevent this type of extraction problem. The gas enters the flutes and counterbalances the pressure against the case wall and also acts as a lubricant.¹

The PM-30's frame is aluminum. The slide and barrel are steel. Interestingly, the barrel is fluted.

Regarding the .22 Magnum performance compared to the FN 5.7x28mm round, read this article.

Specifications
Caliber	.22 Magnum (.22WMR)
Barrel length	4.3"
Slide and Barrel	4140 Steel
Frame	7075 Aluminum
Magazine capacity	30 rounds
Trigger pull	3.5 to 5 lbs
Weight (no mag)	13.6 oz.
Length	7.9"
Height	5.8"
Grip Width	1.1"
Muzzle Velocity (40 gr)	1230 fps
Expected Availability	Quarter 2, 2010
MSRP (Price)	$415

Oleg Volk has taken some photos of the pistol...

UPDATE: Bill pointed out that the Grendel P30, which was manufactured in the early 90s, was designed by George Kellgren, the founder and chief designer at Kel-Tec. I suppose the PMR-30 is an improved P-30.

Early next year North American Arms will be selling “The Earl”, a “five shot single action 1860’s-styled mini-revolver chambered in .22 Magnum”. The revolver is named after the gunsmith who developed it.

Click to expand.

To complete the mid-1800’s look they have included a fake reloading. It has a 4″ octagonal barrel and weights 8.6 oz. The MSRP for the standard model will be $289. A model with a .22 Long Rifle cylinder will cost $324.

More info at NAA.