I'm thinking a turkey or fish fryer burner is a must to get the volume of heat required. Every drip of shot is pulling heat out of the pot.
I think about making shot but then in the end decide to put it off so the cost can go into other things. I wish there were plans for making a small shot maker. I would enjoy being able to do it, just don't need the volume of shot that warrants buying one. And don't really have the free time to make a good one.