A buddy made up some wax boolits using 1 pound of paraffin, 4 oz beeswax and 2 oz marine bearing grease. They’re soft when he cuts them from the cake. He fires them right away and has noticed that they get very hard when fired. They’re punching through aluminum cans and cardboard. He’s using magnum primers in .45 Colt and no powder. When he recovers them they are much harder than when loaded. Any ideas on what causes them to get so hard?