jp1: Wheel weights should work just fine in your 30-30. You might want to add a bit of tin to aid in mould fill-out. If you're using a boolit designed for gas checks, and you're putting them on, then air cooled will work fine. If you're using a plain based boolit, or not using gas checks with a boolit designed for them, and you're pushing them fairly fast you might consider water dropping the boolits to harden them a bit, although I personally have never felt a need to water drop my boolits.
Also, I'm curious, when you malt down the lead, do you use beer, or powdered malt? :)