big al hunter
New member
. I rotate between two double cavity molds. Between the time I'm releasing bullets or refilling the lead, the other mold is resting on the aluminum plate under the pot.
I use aluminum molds. I preheat them by resting the mold on the top edge of the melting pot. It heats up with the lead. When the lead is ready, so is the mold.
Something to remember with aluminum. It dissipates heat very quickly. And if you place something on aluminum it transfers heat from that item very rapidly compared to other materials. By placing your hot mold on the cold aluminum base plate your mold is cooling more than you would think. Steel and brass molds tend to heat up slowly, but they cool slowly too, so you might need that time using 2 molds to be efficient.
Try running one mold at a time. As soon as the lead gets hard on the sprue, empty the mold and refill it immediately. The mold will not cool as much, and you don't get wrinkles near as often. When I keep that pace I only have to reject the first 2 or 3 casts. Sometimes only the first one.
The size of the bullets makes a difference too. I have to move pretty fast when casting 124 gr 9mm. I have to slow down a bit with 300 gr .452. I turn the pot temperature up a little on 9 mm and down a little on 452. Just some things to think about and experiment with.