The .30 Newton cartridge was designed by Charles Newton in 1913, based on a German caliber of the period, the 11.2x72 Schuler.
Newton originally called the cartridge the 30 Adolph Express after Fred Adolph, a well known immigrant gunsmith from Germany at the time, who had proposed the idea of necking rimless German cartridges down to produce a high velocity hunting cartridge.
[1][2] The Newton Arms Company was the only manufacturer of commercial rifles chambered for this cartridge.
Although suitable for any large North American game, it is an obsolete round no longer manufactured.
[4] Cases for 30 Newton can be easily made from .375 Ruger as they are very similar other than the caliber of the case neck; so much so that many assume Ruger based their cartridge on the 30 Newton case.