I downloaded this the other week and am on my second reading. 181 pages of every thing you ever wanted to know about casting bullets but didn't know who to ask.

http://www.lasc.us/Fryxell_Book_textonly2.pdf

It's called "From ingot to target: a cast bullet guide for handgunners." by Gen Fryxell and Robert Applegate. It's a must read for every bullet caster experienced or beginner.

I've posted this thread on the reloading section as it's equally pertinent to both.