What velocities are you running them? I’ve tested my rifle all the way to max loads recommendations for the 460 S&W with no pressure signs. Here are my groupings:
http://450bushmaster.net/viewtopic.php?f=8&t=15355
I ran out of AC boolits and have a good 1,000 plus made up that we’re WQ when I made them a year and a half ago. Hopefully they softened up a tittle when aging. They tested around 16 BH a month after I casted them if I remember. They were the first boolits I casted and didn’t realize I would never need a WQ boolit for anything accept dinosaurs at the time.