Not too many of these fad cartridges get popular or stick with us. Yes they work but usualy isnt worth buying the dies and exspense. I have the .22 jet, the .256. The .357 maximum was a fad that dident last, the old .357/44 bain and davis, 45 gap etc. People wont pay for the unusual on used guns like had they not been altered etc.
Hey! I bought a beautiful first year winchester model 70 .22 hornet. Took it out and discovered it had been rechambered to .22 K-hornet. Had it not been messed with today that gun would be worth many times more than I could get for it as is. Actualy, the K-hornet is a better cartridge than the standard hornet. Thats what I mean when I say they arent worth messing with. Rarely will you get your money out. Might be okay as a project just to prove these things work. When I was young and dumber 40 years ago I converted a winchester model 73 to .38 special and a 92 to .357. Besides costing me the exspense of the work I instanly lost all collector value and probley sold them for less than a fraction of what they would bring now unmolested!