All you need to do is smoke or put a little talcum on the bullet and the shoulder. Chamber the cartridge, then take the cartridge out of the rifle . Inspect the cartridge. If your bullet is too long the bullet will be marked by the lands. If you did not properly bump your shoulder back, then your case shoulder will be marked. If neither are marked then it is in your case taper, and you probably set your sizer wrong. Easy fix, just take your time. Try this first before you spend any money. Tom.