About 1937 a man named Gebby and an associate, J.B. Smith completed the work on the wildcat 22-250, simply the 250 Savage case necked down to .224 with a 28 degree shoulder. Some years later, P.O. Ackley increased the 22-250�s case capacity by re-forming it by almost eliminating its body taper and giving it a 40 degree shoulder. Case capacity essentially duplicates that of the 220 Swift. 

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