I was trying to get some .308 prepped for loading but when I resized and de-primered, I'm getting a dent in the case right below the neck. Now these dies are about 40 years old, I know age don't matter but they did have a little corrosion in them. It wasn't bad just surface rust, with a little scrub brush and WD-40 they cleaned up good. Could there be a vent hole plugged, too much oil? The brass is also very hard to push in and out of the die. I actually broke a case off into one of the .308 dies. Now I know that ain't right. Any thoughts on the denting of the case?