Twice! On a progressive press that swages primer pockets also. Crimped in spent primers from military brass sometimes stick to the deprime pin and get pulled right back into the primer pocket. Then the primer crimp removing swager will press that spent primer in and at the next priming station when you seat a new primer boom...blue flame as about 50 primers went. Kinda loud too The press is designed so it's not a problem ;^) I wear ear plugs now. Love those presses and will not name them here. I watch for the spent primer to drop NOW. I hope this helps someone.