You may or may not already know about this, but if not, here is a great read that will help out greatly once you start in seriously working on your rifle boolits,
This is how I do a pound cast.
There is also a TON of info over there listed up in the various sticky's that will guide you down the right path to success, if you spend some time reading up and jotting down a few notes here and there. I don't have any idea how many doc's I have that are cut and pasted tidbits of knowledge that I have gleaned from there and the LASC site.
Hope that helps