Because I've already had one Aussie take my name in vain (Love you anyway, Jennie), I might as well address the Australian question, since I've seen it slung about this weekend.
Ignoring the cultural and size differences (24 million vs 300 million), they've kinda become a yardstick for people looking for something to compare it to.
In 1996, the Port Arthur massacre happened. It was huge by anyone's standards with 35 dead and 23 wounded. The only mass shooting that's even come close in my lifetime was sandy hook (27 killed, 1 injured, most of them children).
The resulting ban was more of a registration, licensing and buyback program (for those with guns they could no longer legally own).
The two big questions on everyone's mind:
1. Did it prevent mass shootings? and,
2. Did it at least prevent murders and other attacks?
The answer in both cases? Not really.
But that's because there weren't that many to begin with.
Here's a look at Australia's violent crime levels. If you look at the murder rate, it's dropped from a 1.7 in 1993 to 1.1 in 2011.
But that's only a drop from 333 in 1993 to 276 in 2011.
In fact, violent crime in all categories in Australia peaked in the years following the gun ban, dropping after 2001.
As for mass shootings, they still happened after the ban. The Monash university shooting is the most famous, but there's also the Wedderburn shooting, the Sydney hostage crisis last year. They're less common, but they still happen.
The tool of choice for mass murderers in Australia seems to have merely changed. Fire is the name of the game down under, with the Childers Palace backpackers fire, the Churchill fire, and the Quakers hill nursing home fire, all of with killed 10+ people apiece.
So, there you have it. Down under ain't here, and a ban didn't work for them in the first place. So quit acting like it did.

https://aic.gov.au/dataTools/facts/vicViolentCol.html