Many the nations that adopted the FAL (or L1A1, in Commonwealth terminology) opted to also use a heavy-barreled variant of the same rifle as a light support weapon. In the Commonwealth, this was designated L2A1 and it was used by Canada, Australia, and New Zealand. The Australian model was build at Lithgow and supplied to the Australian and New Zealand forces, as well as being exported to a variety of other nations including Ghana, India, Singapore, Malaysia, Papua New Guinea, and others (total Lithgow production was 9,557). It has a 21” heavy barrel and a distinct folding bipod with wooden panels that act as handguard when the bipod is folded up. Doctrinally, the L2A1 was intended to be used in semiauto most of the time, with the bipod and heavy barrel allowing greater sustained semiauto fire than a standard rifle.
A 30-round magazine was developed and issued, but abandoned before long. It was found to be insufficiently reliable, interfered with prone shooting, and contributed to overheating of the guns. Interestingly, Australia also opted to not have an automatic bolt hold open functionality in their FAL type rifles. The control can be used manually, but the rifle does not lock open when empty. This was presumably done in favor of keeping the action closed and clean at the expense of slower reloading (the same compromise was made on the G3 family of rifles).
This particular example is a registered transferrable machine gun made on a Lithgow receiver imported by Onyx in 1985 with other Lithgow-produced parts, including a 1960 bolt, 1961 carrier, and 1961 lower receiver from an L1A1 originally exported to Malaysia.