sounds like your mould has oil in it try cleaning it out with break cleaner if it is a aul mould you will have to smoke it get a good layer of soot on the inside of it you should be able to get good bullets with your lead temp at 650 to 750 deg. to heat up the mould dip the corner of the mould in the lead for 2 minutes and it will be hot enough then but you have to get that mould clean before you can cast good bullets D Crockett