I have some range scrap ingots bought on this forum, they are nice clean stuff, I am using to cast .44 and .45 SWC for revolver loads. The alloy tests 4B with the pencils. I flux with sawdust and am bottom pouring. I am having trouble with getting nice sharp square corners on the bands. There are no wrinkles on the noses, but even casting as fast and hot as I can (power turned all the way up on the old Lee Drip=a=Matic) about half of the bullets just don't have sharp bands so I have a keeper rate of about 50% or slightly less. My moulds (Lyman and RCBS) look fine and I am pretty careful about keeping them clean. I was wondering if adding a little tin to the alloy might help?
Anyadvice appreciated, thanks, namsag.