Not ashamed. I know what a Kennedy drawer is but not a Kerstner. Only been in tool and die for 40 years though. I've made my own 4 flute reamers in the past...fwiw.You new guys need to learn about single flute reamers. A significant percentage of the old gunsmiths (pre-1970) used to offer that service to chamber barrels for wildcats and oddball cartridges. Imagine turning a piece of drill rod, or similar round stock down to reamer print specs (+ .003-4"), then annealing it. Next, mill that blank in half lengthwise. Then, temper and grind a cutting edge to match the print. You can cut one chamber or die, perhaps two with it. My old gunsmith* here in Idaho had a Kerstner drawer full of them.
ISS
* he learned his trade in the AF during the Korean War.
And, please; don't tell me you do not know what a Kerstner is. Please.