normally I preheat my molds with a hot plate I bought specifically for preheating, with my aluminum molds I run it just below the hottest setting until my pot reaches casting temp, which is between 750 and 800 depending on mold. Ive noticed with my brass molds the hot plate on the hottest setting doesn't get them to temp fast enough so I end up casting for awhile (maybe 50-80 bullets depending on mold) before it drops good bullets, I could leave it on the hot plate longer but its convenient to run them both until the pot is ready and go to work. The two I have most of the issues with or HP molds. it could just be the pins and I haven't tried heating slightly with a torch. I was mainly curious to see what everyone else is doing. I know there are multiple threads but id like to stick to the idea that when to pot is ready the mold should be also.