I think the action would work fine for the .219 Zipper. One may have to rework the extractor, and definitely have to swap out the rotor. Personally I would start with an action that originally was used for a .30/30-class cartridge, but WTH, just a little more bother involved with using a .300 action. By far the biggest stumbling blocks would be having a .219 barrel made and fitted, with all the hassles of finding a .219 reamer in this day and age. Then there's the matter of handloading dies.
