Doug,
Another approarch might be using the Lee 30-30 Collet Neck Sizer with their 25-06 collet installed. They dont have a 6.5 collet but, collets being what they are, the .257 may work. You would have to turn your own mandrel/decap stem also.
I'd be inclined to order the Collet NS die (alone, not set) and the 25-06 collet as a part.