I do not know how difficult it is to find modern-made factory 9mm Steyr ammo, but it is fairly simple to load your own. The cartridge is very similar to the Spanish 9mm Bergman-Bayard (aka 9mm Largo), and Starline makes several 9x23 cases that will work perfectly in the Steyr pistol. It can usually be loaded using 9x19mm or .38 Super die sets. The bullet diameter is the same as that used for the 9x19mm Luger, and any 9mm bullet can be used. Chile also used the 9mm Steyr pistol, and it is not too difficult to find the old Chilean 9mm Steyr military ammunition which was usually made in Germany. I have two unopened boxes of it in my collection.