I feel your pain.
The lead ingots I buy are roughly 5-6 pounds so each one will go into the RCBS furnace but have run into trying to cut lead before and never found a really good way. A friend used to use his band saw to cut up big ingots but the lead quickly gummed up the teeth. I've used an axe to chop on it but it's so soft it just bends.
The bar solder can be scored with diagonal cutters and then bent back and forth to break it. But really big hunks of lead still give a problem.
