My take on the Australian situation was that most Australians didn't see gun rights as a fundamental right. They weren't seen as truly needed for self-defense or defense against tyranny.
Those who proposed that were nutters (a quote). The majority of gun owners also didn't make the rights argument but tried the sports argument - that Aussies must have a sport and this was theirs. So leave it alone. But the sports argument went nowhere after their rampage killing.
This is a take from some Aussie social scientists - some anti and some who are progun (from the rights perspective).
It's a problem of competing evaluations of guns. Certainly, they are dangerous and used for evil. Trying to negate this argument with the tool analogy and blaming it on the user, doesn't go anywhere outside of the gun choir. You must make the case that the utility of the firearm outweighs the bad behaviors that are enhanced by firearms usage.
The good usages are:
2. Defense against tyranny
3. Backup for your armed forces
In the USA, 1 has the most traction as in Heller. Some folks buy into 2. No one buys into invasion scenarios by other nations. You might argue Katrina and the border but Red Dawn makes you look silly.
Sports - kind of a variant of the tool argument. Folks are trying to make ARs harmless by pointing out sporting uses. However, outside of the choir, that doesn't fly either. You could play with other things and guns
You have to make the case on 1 and 2. If a country doesn't see that - then you are sunk for gun rights.