My first few attempts to neck size brass with the Lee collet die were excercises in total frustration. I either didn't get enough neck tension or I got buckled necks. I quit trying and it sat on a shelf for about a month before I tried it again. I was determined to get it to work, however. I took it apart and examined everything and it occured to me that the parts were just too roughly finished to work properly. There were burrs around the mouth of the collet sleeve that were making gouges in the collet. So I polished the collet and collet sleeve (where they come in contact with each other) going up to 1500 grit wet/dry sandpaper. I reduced the mandrel by .001". When I reassembled everything, I applied a little dab of grease around the mouth of the collet sleeve.

Well, my efforts paid off. The collet die has worked perfectly (and quite effortlessly I might add) since I gave it this tune up. I have performed the same procedure to subsequent collet dies and they have all worked great.

I don't know when the patent expires on this die, but when it does I hope one of the other companies starts making their own collet die. It's a great concept, but I think Redding or Forster would do a much better job with it. Lee might have come up with the idea, but their execution of it leaves a lot to be desired.