.30-40 Krag
The .30-40 Krag, also known as the .30 U.S., .30 Army and .30 Flanged Nitro Express (Purdey) was a rifle cartridge developed in the early 1890s to provide the U.S. armed forces with a smokeless powder cartridge suited for use with modern small-bore repeating rifles to be selected in the 1892 small arm trials. Since the cartridge it was replacing was the .45-70 Government, the new cartridge was considered small-bore at the time.