............so we all agree that that you would ruin an aluminum mold.
Brass will fuze to an iron or steel mold, how do you think they repair cracks in cast iron?
http://en.wikipedia.org/wiki/Brazing
So we all agree that you would ruin a steel/iron mold.
Your left with casting bar stock and machining them or lost wax casting bullets and then machining them.
Then I would explain to you why its easier to turn in the brass for scrap and buy lead.........or maybe I just did.
Sorry to burst your bubble, just trying to save a man from destroying a mold.