http://www.rcbs.com/downloads/instru...ndTrimDies.pdf
http://www.midwayusa.com/Find?userSe...eck+reamer+die
Reamer dies are close to $80.00, the reamer that goes with the die run close to $80.00, not for everyone, but if centering the hole in the neck means anything, the reamer/die combination is the way to go.
Then there was Lee, he furnished a neck reamer in his Target Model reloading die set.
As I have said before, donuts are produced by bad habits, a builder/wildcatter/reloader was having trouble with 22/6MM Remington Ackley Improved rifles he was building, when fire forming he had 60% failures, so, I formed 20 22/6mm Remington cases using 30/06 cases and 25/06 cases, the neck required reaming when the neck was sized down to .243 and again when the 243 was necked down to 22/6mm Remington, long story short he had no clue as to the cause of the case head separations and did not understand the cases I formed for him required full length sizing after he determined the length of the chamber, he was happy with the 40 % that did not fail and I thought he was just luck, anyhow he told me none of the cases I formed would chamber.
F. Guffey