Australian soldiers on the Kokoda Track (or Trail) in New Guinea, South-Western Pacific Ocean; c. 1942-43. 
The soldier in the foreground carries an American Thompson submachine gun.

On a difficult terrain

Private R. Gaudry of the 2-3d Battalion, AIF (Australian Imperial Force) with his Owen submachine gun in  New Guinea; South-Western Pacific, 1945.
The Owen sub was the only entirely Australian-designed and constructed service submachine gun of World War II and was used by the Australian Army from 1942 until 1971.

Fighter with his own country's weapon

Australian troops of 2/14th Battalion, 7th Division, come ashore at Yellow Beach, Balikpapan, Netherland East Indies; 1 July, 1945.