I've been smelting my cache into ingots and have another question. I hand sort all the lead as to type/source/whatever. example is battery cable ends, sorted and smelted out about 4lb. ie 2 ingots..... Well some of the ingots, mini, medium and regular muffin pans, have what I call "shrink" holes in the center. It is where the pour shrinks and leaves a "crystal" lined hole in the center of the ingot. This is not in all of the lead but some of the alloys have it in almost every ingot I poured. What is this telling me? The soft types seem not to have this. Any explanation? Thanks, 10