The NSW government wants to change prohibited weapons laws so offenders can be jailed for up to 14 years for illegally possessing crossbows, grenades, flamethrowers and other "military-style" arms.
Under proposed changes to the Weapons Prohibition Act 1998 and the Weapons Prohibition Regulation 1999, such weapons would be specifically listed as military-style prohibited weapons, Police Minister Tony Kelly announced on Sunday.
"There is no military-style weapon category at the moment, so we are creating a new category with a higher penalty," he told reporters in Sydney.
"This will better facilitate harsher penalties - up to 14 years imprisonment to be considered during the court process."
Mr Kelly expects the amendments to receive parliament's full support, including The Shooters' Party.
"I would expect this legislation would go through unanimously in the upper house," he said.
"I'd be very surprised if anyone objected to this legislation."
Members of the public are invited to comment on the draft Weapons Prohibition Amendment Regulation 2009 before it is introduced to parliament.
"It won't be enacted until after September," Mr Kelly said.
Of the 459 people who have a legitimate use for military-style weapons, most are collectors.
Many of the weapons are kept at RSL clubs.
"If you go to any of the RSL clubs you'll normally see some relic from past wars that has probably been disabled," Mr Kelly said.
"The government would obviously not like to ban those sorts of memorabilia that are there for a lot of those soldiers that have passed away."
Mr Kelly believes military-style weapons that come into the hands of corrupt people are most often imported illegally.
"Obviously a lot of these weapons are imported from overseas illegally and they may come on shore by ship in containers," he said.
"But customs can't check every container, however, they do check a lot more these days."
At a recent raid on a south Sydney unit, a fully automatic AK47 assault rifle was discovered among other items including several handguns and police uniforms.
The premises were occupied by members of an outlaw motorcycle gang.