Haven't cast any range lead yet, but I think what you're saying is that trying to melt INTACT plated or jacketed bullets is not such a good idea, so you should "smoosh" them first, break 'em up? Then just skim the floaters off your lead. Lead doesn't expand like water (to steam) but there's no real way to know what else might be lurking inside. Good advice! I learn something everytime I get on here.