I've got a question about bullet casting alloys for ya, but a little background first.
I started casting .490 Round Balls for more muzzle loader 20+ years ago. I was using pure lead that I bought from my club but I have no idea where the club bought it. I never had any problem turning out high quality (visually inspected only) balls. I wouldn't necessarily call myself an expert but I can tell poor balls that are that way from incorrect mould heat.
Anyway, my problem is this. For my BPCR bullets I've bought some 20-1 and 30-1 lead from Midway. When casting my ML balls I don't remember fluxing and skimming all that much, I did it, but it didn't take all that much. With the alloy from Midway, I will flux and skim, and flux and skim some more. When I think I surely have all the impurities possible out of the lead, I cast bullets. But the bullets still have "scabby" looking places on them and what appears to be flecks of foreign matter in them, they will be smooth and shiny in some places and frosty in others. Is this just "the nature of the beast" when casting with an alloy or is the alloy that I'm getting from Midway just really poor quality? If it's poor quality alloy, where should I be getting my alloy?