9mm Japanese revolver

The 9mm Japanese revolver, also known as the 9×22mmR Type 26, was a cartridge similar to the .38 S&W. These cartridges are not interchangeable. The rim of the 9mm round is much thinner and the chamber pressure is lower than most .38 S&W loads. 
The cartridge saw action with the Type 26 revolver in the Russo-Japanese War, World War I, and World War II in a limited role, but the service pistol of the Imperial Japanese Army was the semi automatic Nambu pistol, which fired the 8x22mm Nambu round, which was comparable to .32 ACP.