I ran into something today that I've never seen or even heard of. I couldn't get my RCBS seating die to seat a 115 BST in a .257 Roberts cartridge. I finally got it seated after REALLY torquing it. But then the loaded case would not chamber in my rifle (it had done so with no difficulty before seating the bullet). I tried another and the same. And another. I concluded that in forcing the bullet to seat that I set the shoulder back. So I tried seating a 115 Partition and it went in perfectly with no difficulty at all. Did this happen because the BST are so long? Could I expect the same problem if I attempted to seat Accubonds or Hornady SSTs? Thanks.