What we have at the moment is a calibre restriction of .38 maximum so in reality .357 Mag is the most powerful we can own providing we shoot competition and fulfill all the minimum shoot requirements and other balderdash that our Govt. tells us too.

The only options you have to own a larger calibre handgun is to compete in either Western Action/Cowboy/Single Action events (whatever your Pistol Club calls it)
OR
Handgun Metallic Silhouette competition.

To do this you need to have your Concealable Licence endorsed by the Firearms Registry. This requires a letter from your club stating that you compete in either of the above and that you will use the gun for competition. It is free and I had mine back 10 days after I sent the application. It requires a Form 4 (Change of Particulars) which is available from any Police Station. Fill them out, post and the endorsed Licence is returned. Easy!!

This will allow you to purchase up to a maximum calibre of .45 so the .44 Magnum, .45 Colt, 454 Cassull are available for Silhouette shooters.

There is no provision for hunting/carrying a handgun so you would be breaking the law big time by using one in the bush unless you can organise something on a Primary Producer licence.

The bottom line is that handguns can be at locked in a safe at your home or if out of the safe it must be in your direct control, in transit between home and range or at the range. Anywhere else you are asking for trouble.

One thing to bear in mind is that if you are a member of a Pistol Club with no affiliates you are restricted to use on that range only and direct travel to and from. Membership of SSAA or other bodies enables you to travel to, and shoot at a variety of ranges and basically means that providing you are travelling to compete it is possible to take your handguns with you (without a requirement to return to your home after the shoot) providing safe storage requirements are met in your vehicle. It is essential that you have your attendance record properly completed at the various clubs you compete at while on your trip.

Several manufacturers produce fine revolvers in .454 Cassull, Freedom Arms (expensive), Ruger & Taurus are all available here and it is possible to shoot .45 Colt through them for cheaper and less recoil practice, much the same as the .44Special/.44Mag. There is also the BFR Biggest Finest Revolver) .45/70 revolver (also expensive). A 5 shot single action job which would make a great companion to a Marlin Guide gun.

SSAA clubs have Handgun Silhouette ranges in most parts of Australia and their indoor ranges at Southport and Ipswich both conduct single action competitions.

Hope this helps mate, don't forget to read between the lines.

The only other option I can see is a direct request to the Firearms Registry for some form of special category to be added to your licence and I think that would be problematic - no provision in the weapons act for any form of self defence, animal or human.