The 9mmX18mm Ultra was originally developed in the 1936 for use by the Luftwaffe, but was not adopted at that time. In the 1972–1973 time frame, Walther introduced the Walther PP Super chambered in the cartridge for the West German Police. The Walther PP Super was discontinued in 1979. The cartridge was made available to the civilian market in 1975.
In addition to the Walther PP Super, the SIG Sauer P230, Mauser HSc-80, and Benelli B76 were also produced in 9×18mm Ultra. The 9×18mm Ultra (.355-inch caliber) is not interchangeable with the 9×18mm Makarov (.365-inch caliber), as the latter uses a larger diameter bullet.
