I used to cast for .30 cal., .357-.38, 9MM, .41, .44, .45, & .54. Various bullet styles in these calibers. I did a lot of experimenting with lead alloy mixtures. I used plumbers bar solder, (it has a lot of tin), pure lead, wheel weights (some tin), car battery's (not much lead here). I settled for as near as I could get to #2 alloy for a all around mix. For the hotter loads more tin (more penetration, less leading). If I recall leading will start around 1300 fps., from that and under, after several rounds run a few factory jacketed bullets, helps wipe the lead out. Over 1300 fps. use a gas check, and more tin you can get into the low 2000 fps. with proper lube and sizing, and still get some mushroom on the bullets.
This is a lot of fun and lowers the shooting cost way way down. It's been a lot of years since I've done much, I have well over a 100 lbs. in 1 lbs. bars of various mixes. Just give it the old scratch test, pour a 1 lbs. bar and scratch it with a knife point to see how hard it is. Pour a bullet, shoot it into a rotten stump, dig it out and see the results.
I used the LYMAN RELOADING HANDBOOK for a reference.