There is also a section in Lee's Modern Reloading for determining appropriate cast bullet loads. It's a formula for doing so without using fast burning pistol powders.
Done properly, cast bullets can been driven virtually as fast and accurately as jacketed in most rifles. It takes experimentation and patience however.
If you are just getting into casting, I would say to stick with the lower velocity loads and use a gas checked type of bullet and a hard alloy. Also proper sizing is the key. Usually to the THROAT diameter not the groove diameter. Ideally, the throat diameter should be the same or slightly larger than the groove diameter.