I have a couple of .32 Rf cartridges in my collection. My wife's grandfather had one, a Remington rolling block, and it was passed on to her uncle. A neighbor has a .32 and I bought him some cartridges for it some years ago. I don't think he has even fired one, but wanted to be able to if he took the notion. My understanding is that the problem with these cartridges in comparison to the .22 LR was that they were more expensive and had a much higher trajectory. According to Cartridges of the World, Remington was working on a high power .25 caliber rimfire just before WWII, and that the development of the .22 Magnum killed the possibility of continuing the .25 caliber.