now that setup is just fascinating. I've been toying with the idea of building a casting setup that will bring the mold up to the optimum temp so that each cast fills out the same. I had hoped to minimize the number of casts needed to bring the mold up to temp.
Can you describe how yours works?
Get yourself a hot plate stove. The small single burner type you can find at wally world or even wallgreens. Set at medium, place the mold on top while the lead is melting in the pot. When the lead is ready to cast, so is the mold, you should get good boolits first cast. If the hot plate has coils, it's wise to put a separate steel or aluminum disc on it the set the mold on. Some use an old circular saw blade.
There are no gas fired casting pots out there. Now, I'm not talking about using a cast iron pot over a makeshift propane burner. The excess heat generated will make the coldest blooded person sweat. AND
there is no way to control the heat. By that I mean to make the flame heat to a desired temperature. Temp. control is the basis of good boolits. Without good temp control, you'll get inconsistent fill-out and weights.