You might have more luck paper patching a lead bullet designed for a 38/357. They would be about the right diameter to patch out to 0.368 for your 9.3. If you're just plinking a RN design will probably feed better.
This seems like the best option, in my mind. Round balls are fun, and fairly accurate to 50-70 yards, but they are not as precise in my experience as something that has more bearing surface.
