Reading a fair amount about reloading issues with the 9mm - particularly problems with resizing, glock bulges, etc. It occurs to me that a collet type die might solve a lot of 9mm problems - but I don't see that anyone even markets such a beastie.
I was thinking that if the die body housed a collet that was factory min or maybe nominal when closed then the taper issue and lube issue pretty much go away. The outside of the collet would be tapered and would ride inside the die body which would have a corresponding taper so that as the collet were driven into the die the collet would squeeze the brass to factory specs. Set it up so that the collet projects down 1/8" or so below the body of the die. When the collet contacts the shell plate and the brass is in place, then the collet and brass get driven into the die body. Put a 20 lb or so valve spring above the collet to push the collet back down and open to release the shell.
It doesn't seem as though that would be a whole lot more expensive than the titanium nitride carbide rings etc that are out there now.
I was thinking that if the die body housed a collet that was factory min or maybe nominal when closed then the taper issue and lube issue pretty much go away. The outside of the collet would be tapered and would ride inside the die body which would have a corresponding taper so that as the collet were driven into the die the collet would squeeze the brass to factory specs. Set it up so that the collet projects down 1/8" or so below the body of the die. When the collet contacts the shell plate and the brass is in place, then the collet and brass get driven into the die body. Put a 20 lb or so valve spring above the collet to push the collet back down and open to release the shell.
It doesn't seem as though that would be a whole lot more expensive than the titanium nitride carbide rings etc that are out there now.