Private gun owners are stockpiling arsenals of more than 300 firearms in suburban homes in some parts of the country, according to new data obtained by the Greens.

Key points: Police data reveals the top 100 private arsenals across NSW

Police data reveals the top 100 private arsenals across NSW In the Sydney suburb of La Perouse, one person owns 305 guns

In the Sydney suburb of La Perouse, one person owns 305 guns Greens MP David Shoebridge said the caches were "honeypots for criminals" and posed a risk to public safety

The trend is thought to be driving an overall increase in gun ownership nationally.

Gun-control advocates say the private caches are "honeypots for criminals", and also pose a public safety risk if their owners become mentally unstable.

The most comprehensive figures are in New South Wales, where figures obtained under Freedom of Information laws from NSW Police reveal the top 100 private arsenals across the state.

They include the exclusive Sydney suburb of Mosman, where one person owns 285 guns; in the south-eastern area of La Perouse where an individual owns 305 guns; and in North Sydney, where someone owns 268 guns.

NSW, the gun state

In Newcastle, one person owns 310 guns in the central suburb of Cardiff. The biggest cache of 312 firearms belongs to a single owner near the regional town of Tamworth.

The March 2017 figures exclude licensed collectors and dealers.

NSW Greens MP David Shoebridge told the ABC that private individuals were able to amass large caches of firearms because under the current law, they could use the same reason to buy their first, 10th or 300th gun.

"We looked at this data and we looked at the public concern about this one individual in the US having a disturbing number of say, 50 weapons, and then we realised that in the heart of suburbia we have someone who's got the better part of 300 guns," he said.

"That's when we have a reality check and realise that we've got a problem and that our National Firearms Agreement is not being properly enforced."

David Shoebridge says NSW could have over 1 million registered guns within just three years. ( AAP: Dean Lewins )

The NSW figures, which were only released after a protracted court appeal, show the total number of registered guns in NSW has jumped by 65,000 in just two years.

There are now 915,000 registered firearms in the state, including registered collectors and dealers.

"If this trend is allowed to continue, NSW will have over 1 million registered guns within just three years," Mr Shoebridge said.

The data shows fewer households own guns, but ownership has become more concentrated.

The highest numbers of gun owners are in northern and central NSW.

The Barwon region, which makes up most of north-west NSW, tops the list with 8,617 gun owners sharing 41,181 firearms. In the Northern Tablelands region there are 7,715 owners; while in the Bathurst area there are 7,423 gun owners.

If you want to know how many guns are in your postcode, the Greens have released all the data online.

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Other states reveal their figures

The Greens requested the same data from other states, with mixed results.

In Tasmania, there are almost 127,000 registered firearms, with the largest individual caches of up to 153, held by people holding a licence for a business or government department.

Gun numbers around the country ACT : 18,967 guns

: 18,967 guns SA : 298,851

: 298,851 Tasmania: 126,910

The second largest stockpile was held by a paintball business in Launceston. The largest private cache had 42 firearms in Hobart.

The largest number of registered firearms by postcode was in Deloraine and surrounds, in northern Tasmania, where there were 17,911 on the books.

In South Australia, there were almost 300,000 registered guns held by about 66,000 owners.

The most guns were in the electorate of Stuart, in the north-east of the state, where there were 16,851 guns.

There, the most firearms by postcode were in the Mount Gambier area, where there were 4,419 firearms.

In the ACT, figures released by the Australian Federal Police show there are almost 19,000 registered guns in the jurisdiction.

The largest private cache of 66 firearms was in the north-western suburbs of Canberra. That area was also home to the highest number of firearms, at 2,748.

"We've been basically stymied in Queensland and same goes for Northern Territory," Mr Shoebridge said.

"In Victoria there is an absolute prohibition on people applying to get this kind of information under Victorian FOI laws, and those laws are designed to hide the problem and prevent the public finding out about gun numbers.

"It's the patchwork nature of the information which really shows us the need for a comprehensive national firearms registry."

Different guns for different disciplines: owner

Sporting shooters and collectors say they will reject calls for restrictions on the guns they own. ( ABC News: Sam Clark )

Sporting shooters and collectors said they would reject any call for restrictions on the number of guns they could own.

One Victorian shooter, who did not want to be identified for security reasons, said he owned more than 200 firearms for both sport and collecting purposes.

He granted the ABC rare access to his private vault to demonstrate how safely his firearms were stored.

"Most of mine are sporting firearms," he said. "Different disciplines use different calibres."

The enthusiast said he had been collecting historic guns since he was a teenager.

"I look at them and I can see the quality."

He said it didn't matter how many guns a person owned, as long as they were properly secured. His are stored in a vault monitored by security cameras

"I believe with the security measures they put in place it's very, very difficult for anybody to rob them," he said.

"We've gone through a police check, we've been fingerprinted, we've basically sat firearms safety courses, and we've done everything we possibly can to show the police we are the most responsible of citizens."

He rejected calls from the Australian Medical Association to store firearms away from residential areas.

"I feel if they were stored, say 500 firearms in one container, that it really does open it up to a risk of being stolen. It's more likely to be stolen," he said.

'They're not stamp collections'

Sydney barrister Michelle Fernando has been an outspoken gun-control advocate since her father, Vincent Fernando, was murdered with a stolen handgun in 2010.

She told the ABC she was horrified by the new figures.

"We're not talking about a stamp collection, we're talking about lethal weapons," Ms Fernando said.

"Gun crime or gun tragedies are real. And if it is an arsenal that can fall into the wrong hands, there's going to be nothing but devastation left behind.

"If an individual wants 285 firearms in their possession, that sounds to me like a collection, and the rules that apply to people who are collectors of firearms should apply to that person. Authorities are not doing enough."

Lobby group Gun Control Australia is calling for an immediate police gun-safe storage blitz for all licence holders who have 10 or more guns.

Spokeswoman Sam Lee said they wanted legislation to limit gun numbers to five per licence holder.

They're writing to the NSW auditor-general requesting a special review of the permit-to-acquire system and legislation.

"There is no checking if applicants can meet storage requirements before the permit to acquire is provided," Ms Lee said.

"All guns are required to be stored in a specific, hard-metal safe with ammunition separated. But the form only asks for the applicant to declare they can store guns safely."