I ran a ladder test the other day with my 300 weaver. I loaded 20 rds and ended up finding high pressure at rd 14. I didn't want to waist the other 6 peices of brass so I pulled the bullets. I figured that I would have to squeeze the necks back down before I reloaded them so I lubed the necks with imperial wax and ended up with a stuck case right out of the gate. Im sending my die to the gunsmith to have it removed. My question is, what could have caused this? I didn't do anything different as far as sizing that I normally do. I've never had this happen and I'm trying to figure out what I might have done wrong.