Owen Gun
From ARRSEpedia
After Australia dropped their unpopular Sten Gun copy (the Austen) they adopted the Owen Machine Carbine designed by Lt. E. Owen (strangely enough!).
This was Australia's first successful SMG design, and despite being reasonably heavy, and having a top mounted magazine, it was both popular and reliable. In use until the '60s, and was replaced by the F1 SMG.
