Just a heads up for those who don't know, Alaskan Bushwheel is now part of Airframes Alaska. They bought the whole operation- tires, wheels, tailwheels, etc.
Carl, I'm curious what you mean by your question "is the key to stopping shimmy?" Shimmy is often caused by an improperly adjusted kingpin nut. There's kind of a fine line between too loose (shimmy) and too tight (sticky handling). I just readjusted my 10" XP Mods tailwheel- tightened the nut all the way and backed it off 4 flats, which is two flats looser than before. It was a bit sticky, now it works great. You can often stop a shimmy by unloading some weight off the tailwheel with some forward elevator pressure.