the company magnum research was making rifles and pistols based on the 10/22 in .17hmr and .22 magnum. looks like they did a recall on some of the ones in .17 though. I've been seeing for a some months now that semi autos in .17 may have some issues. i recall seeing somewhere that .17 was just not intended to be fired from semi auto firearms and the design of the round doesn't support it.

there is also another company called excel arms (excelarms.com) making semi autos in .22, .17, and 5.7x28. interesting stuff...

keltec may be bringing out a rifle in .22 magnum that is based on their PMR30. I would like to get my hands on one of those when they are released.