The 17-222 is similar to the Javelina, but with a little more case capacity. It is also very similar to the .17 Remington. It will have a slightly longer neck than the .17 Remington and should be easily formed from .222 brass by simply necking down the case. The shoulder should remain in its original location. This cartridge has seen limited popularity � probably since it is so close to the .17 Remington. With the fine .222 brass out there, this cartridge does not get the attention that it should. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.