I have had good luck using the Sinclair mandrel to size the inside of the neck. I only shoot my rifles as a single shot, and I orient the brass in the chamber the same every time. I like my brass to "FREE FLOAT" in the shell holder while bumping down the neck, Then sizing the inside with the mandrel instead of the sizing die.

I do not have any precision reamed(or custom match)chambers on any of my rifles. And I doubt if any of my rifles have truly concentric and aligned chambers, and throats. I have found that if I allow the brass to "FREE FLOAT" in the shell holder, that it automatically aligns the bullet while I seat it. But I am pretty sure that you guys have better rifles, and can probably shoot better than I can. But this method has increased my accuracy. And basically that is my major concern.

If I ever get a true target rifle with a perfect match chamber I sure will try what you guys are talking about. Tom.