Why no modern rim-fires bigger than .22? Because the brass case is the most expensive component of a cartridge and large rim fires would be too expensive. Also, I am sure sales of large rim fire would not be all that great inasmuch as many shooters (the smarter ones), are hand loaders and would have no interest. Furthermore, considering that a rim fire would have to be primed all the way around inside the rim, tooling would have to be made just for that purpose...manufacturers would not use the existing tooling. Also, consider that the rim would have to be soft enough for reliable ignition, limiting the cartridge to low pressure. In short, the reason there are no modern rim fires is that it is just a dumb idea... unless of course, there suddenly was a renewed interest in a modern crank-stated automobile.