Yep. Magnum frames only. If you want to buy another mini revolver, you can get a convertible model like mine and still shoot .22 LR. You lose some concealability, but gain a better grip, and the ability to carry a spare cylinder loaded in .22 WMR.
P.S. I'm going to try to get some pics today if I can stay awake. Yesterday I got up and ate breakfast around dinner time, then went back to bed for the night.