Australian Dept of Defence D/l\D on the receiver

[Kiwi]

Not sure of that logic, 9mm was not a common round outside Europe. Japanese did not use it.
Other than the Sten, the British did not use it. The Sten was because they were for use by Resistance and the 9mm WAS the available round in Europe.
More like a capture from WWI when Australia annexed New Guinea to deny German raiders a base.
Look up the SMS Emden

[Doubs]

Originally Posted by Kiwi

9mm was not a common round outside Europe. Other than the Sten, the British did not use it.

The Brits used 9x19mm in the Inglis Hi-Power and Sten. Australians used 9x19mm in a number of firearms including the Sten, Inglis Hi-Power pistol and Owens Gun. 9mm was well know outside of Europe long before WW2 erupted.