There wasn't one. They used whatever guns they could get, and many soldiers on both sides of The War Between The States used their own guns.
The standard issue rifle of the Royal Australian Army is the F88 Austeyr. It is a variant of the Austrian made Steyr Aug, manufactured under license.
Many soldiers of Australia used British equipment, most notably the Lee Enfield which was the British standard issue rifle of the time
M14 was standard issue military rifle before m16.
There are a lot of weapons which are standard issue. Assuming you're referring to the service rifle, it's the L85A2.
The standard issue RCMP gun is the Smith & Wesson 5946 9mm Double Action Only pistol.
100-1000 or more USD
Standard issue rifle for British Commenwealth troops (which included the Anzacs) was the .303 calibre Lee Enfield rifle.
, The Mosin-Nagant is the issue rifle of Russia/The Soviet Union from about 1891 to about 1945-1946 and was kept as an alternate issue rifle until recently. Regards, Josh Smith Smith-Sights.com
The Mark one and two Enfield Bolt Action Rifle in calibre .303 were the standard issue rifles (Australia) in World War I.
Austria, Australia, New Zealand, and Ireland use it as their standard issue rifle. Several other military forces issue it to select units.
the l96 is a standard issue British army sniper rifle with high power and very good range
it would have been his trusty 8mm bolt action mauser