The three-month national push will use social media, advertising and community events to encourage Australians to dob in neighbours, family and friends to Crime Stoppers if they suspect they have an illegal firearm.

Since the nation's first permanent amnesty came into effect in July, 11,000 guns and parts have been handed in.

They included rifles, shotguns, handguns, a crossbow and a flamethrower.

"That's 11,000 firearms that are not out in the community now, potentially killing or maiming hundreds or thousands of people," Home Affairs Minister Karen Andrews told reporters in Melbourne on Thursday.

A three-month amnesty in 2017 also led to the surrender of 57,000 firearms, but there are still an estimated 260,000 in circulation across the country.

Assistant Minister for Customs and Community Safety Jason Wood said the second phase of the campaign was about cracking down on people who were yet to make the most of the amnesty.

"If you do not hand that illegal firearm in, you may be caught by the police and potentially go to jail," he said.

The amnesty applies to illegal guns that have not been used in a crime, Mr Wood said.

Australia has not had a mass shooting since the Port Arthur massacre in 1996, when 35 people were killed and 23 wounded.

It led to rapid-fire guns being banned from civilian ownership except with restricted licences under reforms by the Howard government.

But Crime Stoppers Australia chair Vince Hughes said Australia was still not immune from the devastating impacts of having illegal firearms in the hands of criminals.

"We have seen the tragic loss of life and severe injuries that occur when people turn a blind eye and allow illegal firearms to remain in the community," he said in a statement.

Illegal guns can be surrendered at licensed firearm dealers and police stations across the country as part of the amnesty.

Australian Associated Press