Kel-Tec Uses 3D Printing in RMR-30 Design

RMR courtesy Dean Weingarten

Kel-Tec extensively used 3D printing to prototype their new RMR-30 carbine, a .22 Magnum that uses the same magazines as the PMR-30 pistol. The carbine has a retractable stock, a 16-inch barrel, and uses a straight blowback action, instead of the delayed blowback of the PMR-30 pistol. The RMR30 required a redesign of almost the entire firearm, even though the magazines are interchangeable . . .

Here is a view of the RMR-30 lower receiver alongside a PMR-30 pistol.

courtesy Dean Weingarten1

The changes were prototyped with 3D printing. As covered last year, Kel-Tec used 3D printing extensively in the development of the PMR-30 pistol, especially the magazine.

The 16-inch barrel will use the energy available in the .22 magnum cartridge much more efficiently than the PMR-30, with a 40 grain bullet exiting the muzzle at 1950 feet per second, according to Kel-Tec specs. The cartridge/carbine package would deliver ballistic performance about the same as that of the FN 5.7 X 28 out of the Five-Seven Pistol.

I asked Toby Obermeit, lead design engineer of Kel-Tec, about the reliability of the ammunition, as rimfire cartridges have a reputation of being less reliable than centerfire. Most of my experience with rimfire cartridges has been with the .22 Long Rifle. “.22 Magnum is a step above the .22 Long Rifle for reliability,” said Obermeit. Toby also confirmed that George Kellgren is, in fact, a genius.

RMR-30 Carbine specifications:

Weight Unloaded             3.8 lbs
Weight Loaded (30 rds)  4.2 lbs
Extended Length             29.9″
Collapsed Length             22.5″
Barrel Length                   16.1″

It will be a while before the RMR-30 is available on the market. Obermeit estimated that it might be available in the third quarter of 2014, but he didn’t give a specific date. As nearly all manufacturers are producing at full capacity to meet the demand generated by the Obama administration, I would expect less incentive to develop new products. On the other hand, high sales levels can mean enough profits to fund research and development efforts.

©2013 by Dean Weingarten: Permission to share is granted when this notice is included. Gun Watch