Lee doesn't catalog the 6br in a collet die. You must buy the die for the 6ppc. Due to the design of the collets it works just fine on the 6br. You must buy a seated for the 6br though. A Forester micrometer seater is a terrific choice as 82boy and sharpshooter stated above. If you want the absolute best do like they suggested but if you're like me and like the collet die then you'll need the one for the 6ppc.

Really a fair idea might be to get the Forrester set and add the collet die with them and you can have it for neck sizing if you end up preferring that route.