Just something to get @Linz and @22F to froth at the mouth.
The Australians called it Owen machine carbine gun and used it into the 1960's. Some 45,000 were built. It had the notable advantage of having gravity assist the magazine feed and the top mounted magazine meant diggers could get more familiar with the ants and and giant centipedes that inhabit much of the Pacific islands.
https://en.wikipedia <DOT> org/wiki/Owen_Gun