I got this off the Internet when I did a search on your question.
Choose a heat source as well as equipment used only for melting. A cast-iron skillet, aluminum slotted spoon, and aluminum ladle make a good starter set for DIY lead melting, but make sure you use them only for this task—never for cooking food! Since lead melts at 621 °F (327 °C), you also need a powerful yet reasonably safe heat source.
In addition, I have found better results when I was casting larger diameter round ball (.820 and .980) if the temperature was hotter than that. IIRC, the .980 ball seemed to like 750 degrees. .610 and .715 liked 700 degrees, and I think .535 and smaller came out nice at 650. I never really enjoyed casting ball, so I just went for what seemed to work and didn't show inferior results.
Enjoy!!
John (Bigsmoke)