They are heavily restricted in various states in US also, background checks, 6 week courses, finger prints, demonstration of ability to use… what is the difference between states iwht high restriction and low restriction with regard to murder rate? Nothing. (look at Illinois vs Florida and Montana vs CA, MA vs NE etc). Gun control legislation is like putting a band aid on cancer. Hides the problem… for a while.

https://worldpopulationreview.com/state-rankings/murder-rate-by-state

Looking at a map by state, its almost as if economy, high school graduation rate, and population density (especially if you look at a similar map at the city level) has more to do with the issue than any gun control.

As for your claim that hanguns are mostly illegal in Australia. There are plenty of allowed reasons that you don’t get to claim self defence (It’s utterly bizzarre that your government removes your basic right to defend youself and calls itself civilized, do you go to jail if you kill someone who is attacking you with a hammer? No? Then why can’t you do the same with a gun?). Thus, black market or “new” found interest in hunting can get you a new gun.

Even the buyback was a joke. Only 20% of guns came back in from that. This was gun owners getting an an easy way to sell off their crappy guns.

Do you see a single AR-15 in this dumpster filled with shotguns and old rifles? It’s been around since the 1950’s you should see some in there.

https://www.zocalopublicsquare.org/2014/06/05/the-great-australian-gun-buyback/ideas/nexus/

Finally, Brazil, El Salvador, Venezuela, and Jamaica (as well as a dozen others) have stronger gun laws than Australia. Strangely their murder rates are some of the highest in the world. It’s almost as if gun laws aren’t the problem and don’t actually matter. You know, the premise of my original comment.