"So, what's up w/ the pics we saw several years ago of steam rollers crushing mountains of confiscated rifles?"
What's up with that is that most of the rifles in those mountains were not confiscated. They were voluntarily surrendered.
As part of the gun law 'reforms' of 1996/1997, the federal government decided to try and reduce the number of guns in the community - not by making them illegal, but by given people the opportunity to easily voluntarily dispose of them if they weren't using them any more.
Because Australia doesn't really have the same gun culture of the US, there's never been that much of a second hand market for firearms (unless they were in some way unusual). So, if you were dealing with someone who had been duck shooting for 40 years, there was a good chance they had 6 or so firearms lying around the house that were unused, because over the years they'd replaced the weapon they used, but they really couldn't sell the old ones for anything like what they were worth, and the hassles you needed to go through to dispose of a weapon properly were pretty pointless.
These weapons were of concern because they were the ones tending to wind up in the hands of criminals - gun owners generally took care of the weapon they actually use, and they are not stolen very often. But they take less care of something they stuck in the garage in 1985, and haven't looked at since.
So it was decided to try and get those weapons - weapons that were surplus to requirements, that responsible gun owners weren't using anymore and didn't really want anymore, but they hadn't bothered to dispose of.
They had a buyback - where people could voluntarily surrender surplus weapons and receive the commercial value of that weapon in return.
Most of the weapons seen in those mountains were fully legal, they just weren't being used anymore. They hadn't been confiscated - they'd been voluntarily sold by people who no longer used them - either because they no longer went shooting (my next door neighbour was 97 at the time, and got rid of two old shotguns he hadn't used since 1976) - or because they'd upgraded to more modern weapons. 99% of the weapons in those mountains were still legal, and people could have kept them if they'd wanted to.
There were a small number of weapons that became harder to own - and quite a few people surrendered those as well, rather than go through the process of getting a higher level licence. A few people found themselves unable to get a higher level licence even though they were able to hold the licence they had - typically these were people with criminal convictions that were more than ten years old - in Australia, for minor crimes, after ten years without committing another crime, your conviction is often considered 'spent' - no longer relevant. The rules for a basic licence in some states allow people with non-violent spent convictions to own basic firearms - but the higher level licence requires no convictions ever.
There were a very small number of weapons that became so hard to own, they pretty much became illegal. But that was less than 1/10th of one percent of the weapons collected.
People *chose* to surrender *some of* their weapons if they were no longer the weapons they used.
As for the violent crime rate, Australia doesn't really have accurate figures from before 1996 on many violent crimes. It looks like the level of violent crime initially rose slightly (mostly caused by drugs, in my opinion, - from around 1999-2002, Australia's drug problem got out of control) after 1996 - but the rise started before 1996 and continued at about the same rate after. It was already going up and it kept going up at the same speed. It is now starting to decline.
But the violent crime rate really is a pretty separate issue from gun control in Australia. Very few criminals use guns, very, very few citizens ever use a gun to defend themselves.
Really, Australia's gun laws weren't intended to deal with general crime - they were specifically aimed at stopping another massacre like Port Arthur, and on that specific issue they seem to have worked - Australia had a single gunman massacre on average once a year from 1987-1996.
It hasn't had one since then. That's why they introduced the laws - because frankly the laws we had before 1996 made it way too easy for a total nutcase to get a gun. Martin Bryant, the gun who killed 35 at Port Arthur, was obviously mentally deranged to anyone who knew him, and was already under suspicion of having committed two murders - and the laws in his state in 1996, let him buy high powered weapons, without any real controls at all.
The simple fact is, while we have more controls than we had in 1996, Australians who want to own firearms can still do so quite easily. The number of Australians who own a firearm is still about the same as it was in 1995.
I live here. I own guns.