If you're an old hand at casting, I'm sorry for this little bit of nuisance, if not, the first thing ya need to do before using the mould is to clean it. Any oil in the cavity will wreak havoc on your bullets till it's burned off, and that can take a while, HOT soap and water followed by alcohol or other degreaser then allow the mould to dry by warming it while you melt the lead. If the mould starts to become difficult to open a teeny tiney bit of bullet lube in the joint, don't let it run into the cavity or you'll have to burn it out again. As mentioned, after the mould is hot and dry, smoking helps the bullets to drop out easier. There is nothing difficult about casting once ya figure out the little stuff.
B.Ford