ASSAULT rifles, hand guns and thousands of bullets have been seized as police strike forces across NSW crack the largest weapons supply chain in the state's history.
Up to 20 AR-15 rifles, the make and model used in the Port Arthur massacre, have been found along with five hand guns and varying calibres of ammunition at a residence south of Port Macquarie.
In Sydney detectives discovered 20,000 bullets and casings, a semi-automatic pistol and additional parts for AR-15 assault rifles.
Equipment suspected of being used to manufacture and modify firearms and assemble ammunition was also found, as well as manuals and books on the manufacture of firearms and military paraphernalia.
Police will allege the highly sophisticated operations are linked.
They believe the weapons were being prepared for sale to Sydney's organised crime network.
The AR-15 rifle can fetch up to $25,000 on the black market.
Acting Deputy Commissioner Specialist Operations David Hudson said police had broken an illegal firearms supply chain and prevented military grade weapons from falling into the hands of criminals.
"The operation is testament to the NSW Police Force's ongoing focus to stamp out gun crime, but it also demonstrates that there is much more work to be done in the detection and prevention of illegal firearms being brought into this country," Mr Hudson said
"In recent weeks, the community of NSW has again had to experience a number of public-place shootings, including several where people have been seriously injured.
"To resolve this we need to continue to work in partnership with other agencies to address the constantly-changing methods criminals are using to obtain illegal firearms."
A 54-year-old man has been charged and refused bail.
Police expect to make more arrests.