Well first thing you need to do is read the Redding web site. You need to do some math before you can order a bushing. Second, although you didn't ask I am going to give you my two cents. I have spent a ton of money on these fine quality dies; but I do just as good, if not even better without them. Currently, I use a Forster benchrest seater, Redding body and Lee, yes Lee collet die for neck sizing. If you want to full length re-size redding or Forster is great. Save yourself some money and give it a try.
Doug