Gun ownership has surged 10 per cent in NSW in the past five years, with one gun now registered for every nine residents.
And the biggest rises in gun ownership are in some of Sydney's most affluent areas, postcodes that encompass Neutral Bay, Pyrmont and Sydney's CBD, where the number of firearms has climbed by more than 60 per cent since 2010.
More than 850,000 firearms are now legally registered in NSW.
Newcastle recorded an 81 per cent increase in the number of people with a firearms licence in the same period.
NSW Police Firearms commander Mick Plotecki said anecdotally, the combination of US popular gun culture and a recruitment drive by gun clubs may be behind the rise.
Alarmingly, in 22 of the state's 600 postcodes, registered guns outnumber people.
This includes four postcodes where guns outnumber people two to one.
Liverpool has the highest number of registered guns in the Greater Sydney region with 4689, according to figures obtained by the Greens under freedom of information laws.
There are 4505 legally registered firearms in Chester Hill followed by Horsley Park with 4442 and Bexley with a surprising 4239.
NSW Greens MP David Shoebridge says gains in community safety won since the Howard government's gun buyback program in 1996 have been lost.
"Many people will be quite rightly shocked to find there are many hundreds if not thousands of guns in their suburb," Mr Shoebridge said.
"There are hundreds of thousands more guns now than following the gun buyback.
"Many farmers and primary producers have a legitimate reason for owning a firearm, but this doesn't explain the thousands and thousands of licences throughout metropolitan Sydney."
(Map excludes postcodes with fewer than 200 people, 100 guns or 50 owners.)
The highest number of firearms were in regional postcodes and rural areas with 14,757 in Dubbo, 14,542 in Tamworth and 14,253 in Bathurst. Across Greater Sydney, the largest growth in the number of registered gun owners was in the south-west, the site of numerous shootings over successive years.
Police Minister Troy Grant said there had been an increase in applications for legal firearms ownership but they were for a range of purposes including target shooting, recreational hunting, vermin control and primary production.
"The real concern is illegal firearms which, in the hands of brazen and hardened criminals, are a clear and present danger to our community and police continue to target this illegal activity," he said.
There are now 850,636 firearms registered to private owners across the state compared to 758,802 in 2011.
It is estimated there are close to 3 million registered guns across Australia.
Greens move to ban rapid fire shotgun
The Greens will move to ban a rapid-fire shotgun being imported to Australia this month.
Mr Shoebridge says 7000 pre-ordered Adler A110 Lever Action shotguns were due to arrive at a time when private gun ownership was nearing record levels.
"This is a rapid-fire firearm which fires and reloads quickly, allowing eight shots in eight seconds. Despite this, the NSW Government intends to classify it as the least restricted kind of weapon," Mr Shoebridge said.
He said the ACT had banned the gun outright because it was as dangerous as a pump-action shotgun.
"The Greens will be moving to ban this dangerous weapon as soon as the NSW Parliament returns," Mr Shoebridge said.
