On that fateful day, killer Martin Bryant took the lives of 35 innocent people.

Those senseless deaths were the catalyst for the entire nation, led by Prime Minister John Howard, to change the way it viewed laws that governed gun ownership.

In the years before the shooting, gun deaths in Australia reach as high as 674 in 1998. Those figures ebbed and flowed between 470 and 618 in the years after 1998. But there's no doubt that from 1997 onwards, we witnessed a dramatic fall in the number of people who died at the hands of firearms in this country.

Critics of those laws often use the line: guns don't kill people, people kill people. That may be technically true, but often violent crimes are spontaneous and those who take another life often do so with little or no forward planning. So it makes sense that if there are less guns circulating in society, the chances of someone using one in a fit of rage are greatly reduced.

On the eve of the anniversary of Port Arthur, Mr Howard has been the focus of much discussion regarding his controversial gun laws. Through a gun buy-back scheme, the federal government was able to remove about a million firearms from the streets. And the impact was profound.

Following the changes, the risk of dying from a gunshot in Australia fell by 50 per cent. A joint 2012 study by the Australian National University and the Wilfrid Laurier University found that the buyback cut the firearm-related suicide rate by 80 per cent over the period of a decade.

To make such sweeping changes to gun laws was, politically at least, a risk for Mr Howard. However from a moral standpoint, there was little doubt he felt compelled to bring about sweeping changes.  "I thought if ever we were going to do something dramatic and lasting to change Australia's gun laws to prevent the emergence of a more alien gun culture in our country, this was the time to do it," he said recently.

The changes weren't without their critics. There were death threats made against Mr Howard, which saw him don a bullet-proof vest at a Victorian rally.  But for all the conjecture over whether Australia's gun laws have made the country safer, there remains one fact Mr Howard advocates that's near impossible to argue. "The simple reality is it is easier to kill 10 people with a gun than it is with a knife or a hammer or something else."