For ML balls, you want pure lead. No wheel weights, junk fishing weights Etc. Don't use those little brass molds that come with repro revolvers, get a real mold. What Alex said about Lee molds is true, they are inexpensive and cast good balls when HOT. They do not last long if you cast a lot of balls. You can cast (I did for years) out of a yard sale iron skillet on the kitchen stove, when your wife is not looking, or on a cheap hot plate. You will want a proper lead dipper. I have an extra if you need it. Pre heat your mold after cleaning it of all oil. I use alcohol or break cleaner, it must be clean! Flux you lead. I use a spoon full of bee's wax, and stir it in with your dipper. It will smoke like hell, and catch fire! The fire burns off most of the smoke. If you spill the molten wax your house will catch on fire!
All joking aside this is best done outside, for ventilation and fire proofness. Fill your dipper with clean lead, tilt mold on side, place dipper in mold, then tip it right side up over your pot. Let the mold fill then keep poring lead into the mold for another few seconds, until a nice large puddle forms on the top of your mold. Let harden. I push the spurce plate open with a stout stick, tap the mold HANDLE and the ball will fall out. In order to not be standing around waiting for the bullet to harden, I cast 2 molds at a time, say a 36 and a 50 so they are easy to sort. While one hardens, I cast the other. Keep water OUT of your mold!! Wear long sleeves, gloves, AND GLASSES. GOOD LUCK.
