[stlbob]

The problem I’m having is cases recess when I resize them, the bulge at the bottom turns into a recess. This recess is where the bulge was about the lower 20% of the case. I know that a lose chamber causes a case bulge in the 10mm and the 40 S&W which is what I’m reloading. Here is what I’m using to resize the brass; first a push through Redding carbide resizing die, this one does not resize the whole case only the base bulge. No problem shows up in this step on the case except some are VERY hard to press though the die, I mean body weight on the handle hard. Second a full length resizing die, again carbide Redding, this is when the cases get the .002-.003 recess where the bulge was at the base, usually on one side but sometimes all the way around the case. I have found the if I use case Imperial lube only 1 in 20 will have the recess and need to be trashed, with no lube 3 out of 10 are trashed. I have tried a second standard resizing die again Redding carbide and the same thing happens. I have allowed the resizing dies to float in the holder of my press. I have tried an RCBS press. I have tried two methods of holding the case in the press, one is a jaw which opens on the downstroke (Co-Ax press) and a standard shell holder, neither of which make any difference. I have tried an RCBS press (single stage). I am not new to reloading but have not reloaded the 40 S&W or 10mm before, this is my first post.
Thanks in Advance,
bob