I'm told that you can reduce or eliminate the leading problem by setting the loads out, slug up, and applying a few drops of Liquid Alox to the nose of each. Let 'em set a few days.
I've treated 15 shells and know that the LA wicks down past the crimp. Haven't gotten arount to shooting them yet. I applied exactly three drops each so there was little weight added and no chance it could get past the wad.
I have shot home brew slugs treated with LA without leading for years so I expect this to work. Bottle of LA only costs three bucks so it's worth a try.