The latest findings from the Small Arms Survey show that Australia is about the sixth biggest importer of weapons, including rifles, revolvers, pistols and ammunition.

Key points: Small Arms Survey shows US remains biggest importer and exporter of weapons

Small Arms Survey shows US remains biggest importer and exporter of weapons Rise in firearm purchases since Port Arthur massacre

Rise in firearm purchases since Port Arthur massacre Law enforcement makes up 5 per cent of arms imports

Law enforcement makes up 5 per cent of arms imports Arms industry growing and becoming more profitable

The survey, which tracks the global trade in weapons, also showed that the United States has remained the biggest importer and exporter of weapons.

Philip Alpers, a public health researcher at the University of Sydney and the founding director of the GunPolicy.org website, said Australia had ranked "surprisingly high" on the list of countries, coming in between sixth or eighth in the world depending on the year.

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"We import a lot of firearms, but that's largely because we don't manufacture any of our own," he said.

Mr Alpers said the high figures that emerged from the survey also included ammunition.

"We are a country of high use of firearms, we have a lot of the indicators: we're an agricultural society, we have high disposable income, we have a very robust sporting and shooting," he said.

"There are many legitimate uses for firearms in Australia, largely primary production, and so it's no surprise that we … consume and buy and import quite a lot of firearms."

Firearms destroyed post Port Arthur have been replaced

Mr Alpers said the number of weapons being bought in Australia had been climbing since the Port Arthur massacre.

"Of course there was a big collapse in the gun industry after Port Arthur, when the initial rush [was] to replace the semi-automatics with single shot firearms, long guns," he said.

He said the rush subsided around 1998, and since then there had been a gradual climb back, with roughly 120,000 firearms now imported per year into Australia.

"We've now got to the point where we've replaced, more than replaced, the million guns that were destroyed [post Port Arthur]," Mr Alpers said.

"But you have to remember that within those 20 years the population of Australia increased by about 23 per cent.

"So we now have almost a quarter fewer firearms per head of population per capita than we had at the time of Port Arthur."

Mr Alpers said fewer than 5 per cent of weapons imported into Australia were for law enforcement.

"Law enforcement … completed its reequipping of police officers back in 2011 when they replaced old revolvers with semi-automatic hand guns, and since then it's just very small numbers," he said.

"Military imports are largely off the books, they are not included in the Customs data, state-to-state transfers, and so on.

"So those figures are civilian firearms and civilian ammunition. The gun culture is alive and well in Australia."

Arms industry is resurging

Mr Alpers said the people who were importing the weapons were arms dealers.

"They're the people who know they can make a profit out of guns. This industry is resurging, it's becoming much more profitable than it used to be," he said.

He said after the post-Port Arthur collapse, several big players emerged who were importing "more and more guns".

"They're finding more and more innovative ways of bringing guns into the country, too — for example, the Adler shot gun, and a new one which emerged this week," Mr Alper said.

"And that's a way of filling a niche of gun enthusiasts who really want a rapid fire weapon.

"And they found a loophole in the law which allows them to bring in a limited number of these guns.

"They may bring in a lot more of them depending on a decision to be made sometime."

Orlando killer used 'weapon of choice'

One of the weapons used in the Orlando massacre was an AR15 semiautomatic, and Mr Alper said that weapon could no longer be purchased in Australia.

He said it was the weapon of choice for the killer at Port Arthur and for most mass killers in the United States.

"It's the most popular rifle in the USA, it was designed to kill as many people as possible in a very short time," Mr Alpers said.

"It's a derivative of the M16 military weapon that was invented … for Vietnam. The estimate is that around four million American households have one or more AR15s.

"And strangely, ironically, there's been a sales boom in these firearms for the past eight years, because the gun lobby in America has built up this fear that Barrack Obama is going to take them away from everybody.

"So we all know that he can't possibly do that, but he has himself said, 'I'm the best salesman there is for these weapons' — because the rumour is that he is going to take them away.

"So there's been an eight-year boom in these fire arms."

Mr Alpers said after a massacre, such as the one in Orlando, firearm sales "always increase".

"The reaction here in Australia to something like Port Arthur is, 'we've got to do something, let's do it quickly, let's do it now'.