Ten years ago my first mold was a Lee six cavity. it took a short time to get the hang of it, and I can pour a lot of boolits,quick...never had a problem with them running too cool. just the opposite. just had to slow down a little. now days when Im shopping for a mold I look at the lee six cavity first. as HOT as it is today I want the boolits to pile up quick!!!.............I have lots of molds, some expensive. but the lee six cavity is my favorite. BTW....I pour with a dipper. ....frontloader