I have about 500 pounds of very carefully sorted CWW in 5 pound ingots and about 400 pounds of very carefully sorted SWW also in 5 pound ingots. All the ingots are marked CWW or SWW. My Magma pot has the CWW in it and when I add ingots I weigh them on a digital postal scale and weigh out 2% pure bar tin. My RCBS pot has the SWW in it and it's the same drill, when I add ingots I weigh them and add 2% Sn. I also have a fair supply of Roto Metals Super hard should I want to experiment with various alloys and Sb percentages but I don't seem to get into much of that anymore. The two WW alloys cover about everything I do these days.