If you are using a short drop shot maker drop the lead into cooking oil in a container about 10-12" deep , it is cheap , doesn't smell bad or smoke , is non toxic and easy to wash off with hot water and detergent and best of all it works . Use carburetor jets for the size , cheap and easy to change , chalk the drip shelf .
There was a shot tower across the road from the gunshop , I am not sure how high the tower was , the lead was melted into ingots of about 20 lbs ,in a furnace at the bottom of the tower . they were sent up the tower where they were put into a gas fired melt pot , the lead was poured onto a gas heated pierced flat bottomed bowl about 3' across, and fell through the air cooling as it went , it fell into a heap at the bottom , it was then was run across big thick glass panes 9- feet wide and 12 feet long and ½" thick , the glass was tilted downwards and the shot ran down the face of the glass , as it ran the uneven shot ran off to the sides , as the shot ran down the glass panes it had to jump gaps between the panes the lightest shot couldn't jump as far as the larger sizes because it didn't have the momentum and dropped into a bin under the gap , this way the shot was sorted into sizes , the uneven shot and unwanted sizes were re melted into ingots in the furnace at the bottom of the tower then sent back up for another go . The whole thing up the tower was run by one woman . The sieve bowl was set to produce one size but obviously many sizes were produced , after sorting, some would be kept ,some would be recycled .