I've owned and used about every type of chamfering tool ever offered on the reloading market, and even more that were custom one-of-a-kind. Currently the best I know of among commercial hand types is made by KM precision. It comes in a couple sizes, and it's main feature, aside from it's obvious superior quality, is that it can be set to cut to a specific depth. Thus insuring that case to case inside chamfer bevels are uniform. It costs more but well worth the difference.