My son and I have gotten most of our equipment together to try our hand at casting. We have two molds from Mihec. After seeing a lot of info on this site and reading past posts we decided to set everything up on our table(inside under ac). We started dry running through the steps if as we were actually casting boolits. It has helped a lot. This way we won't have to learn with a mold full of hot lead. I got to thinking though,are we possibly hurting the molds by doing this. They are opened and closed as if you were cutting the sprue and dumping bullets. What do you guys think?