I have split three Redding 338 Lapua Magnum dies. Two normal FL dies & one body die. The last one split with the FIRST case I tried to size. It was lubed & require little force & when it was just about to push the primer out it went "Click" & that was that. I don't know when I split the others which was why I was being careful with this one. It was sizing Norma brass. I need to put them through a body die as they are hard to chamber just using my bushing neck die. The Lapua brass hasn't been a problem & only needs neck sizing. The Norma load is probably a little strong but the primer pockets are fine ? Does anybody have any ideas why this has happened ?