If you need one get a Forster die. If you call in, ask for Josh. He is a gunsmith, chambers barrels the whole 9 yards. Forster is a small company, and they have some great people working there. Like the above post if you send them in some fired brass i believe they will custom fit it for you.
SAC dies are what I'm waiting for. I ran 300NM a few years ago, and stepped away for a while. I used micron dies. They worked, but i think the SAC dies are going to be the cats ass.