Much of the "science" of cast bullets is wing-of-bat-eye-of-newt stuff.
One site that has good, solid information is The Los Angeles Silhouette Club.
A few of their choicer pieces of information include:
What do lubes do? Spoiler: Seal. Lubing is as much about stopping gas cutting as lubing.
Leading can be caused by bullets that are too hard. And another article. Spoiler: One word, obduration.
|Alloy/Hardness from LASC, KSI from 1.42*BNH formula. Applications from SAAMI specs.|
Just a couple of key points:
Pressures listed are MINIMUMS. Bullets cast from air cooled, clipped on wheel weights should work just fine in 45 ACP given decent lube while water quenched wheel weights are not likely to obdurate and seal.
1:30 tin/lead is nearly optimal for nearly all handgun cartridges released before 1900 during the black powder era.
Air cooled wheel weights are just a tad too hard for standard 1900 era, black powder cartridges like .38 Special but about perfect for +P and +P+ loads in those guns. Given the ubiquitous nature of clip on wheel weights, this may be the single best reason to buy a .357 Magnum handgun; just to be able to shoot +P+, .38 Special cast bullet handloads.
Air cooled wheel weights are also spiffy for early, low intensity smokeless handgun cartridges like .380 ACP ad 45 ACP.
Water quenched wheel weights are good for high intensity, smokeless handgun cartridges like 9mm, 40 S&W, .357 Magnum and .44 Magnum. When combined with gas checks they are also reputed to be excellent for modern, smokeless cartridges loaded to 30-30 velocities (2200 fps).
Oven Quenched wheel weights can mimic full metal jacket performance.
These guidelines do not eliminate the need for fiddling around, but they should provide good starting points. Use a bullet is "fat" enough. Use a bullet with hardness that is appropriate for your load's peak pressure. Use an effective lube (appropriate for pressure and ambient temperature). Breathe. Relax. Aim. Sight picture. Squeeze. Make a hole in the target.