Sounds like there is to much room inside the bolt nose. I always bore mine out and silver solder a bushing in to make a nice neat installation .140" depth and about .005" over case head diameter.
Exactly! I have had this happen a few times and what Dave suggests has fixed it 100% of the time.
This bolt is for 223 Ackley, Bushing silver soldered into bolt nose. Nice tight fit on the cartridge base.