What type of lube are you using. I like the LEE lube. It comes in a toothpaste tube form. You rub a LITTLE on the brass and resize, then wipe it off with a cloth. It is slower than a spray though.

I had some .308 cases do the same thing and I found my die (neck sizer only) was sizing the neck diameter too small. I adjusted my die, never had the problem again.

The dented cases sound like too much case lube.