I have a 92 Miroku Winchester in 44 mag. I also have a 240 grain plain based bullet mold for it. I'm wondering how fast I can push the plain base bullets before causing leading problems. I usually use gas checks in rifles but really don't plan on driving these at top speeds. Would like to push them around 1300-1400 fps if it won't damage the bases. I generally push plain base boolets around 700-1000 fps in my short guns.