Primers Backing Out

[Catfish]

I believe that you have to have lite loads and bad head spaceing for this to occur. I have fire many rounds while fire forming brass that I knew the head spaceing was off when I fired them, but when fired with stiff loads the case come out prorerly head spaced and if alittle to stiff the primer will be flattened but still flush with the head of the bullet. I have also found over the years that you cannot fire form with loads that are loaded to lite, which is in essance what you are doing with these loads.