As yet another mass shooting in the US resonates, there are fresh warnings firearms manufacturers are targeting Australia with a new generation of rapid-fire shotgun.

The gun control lobby is calling on federal Justice Minister Michael Keenan to ensure all lever-action shotguns face tougher restrictions after it emerged yet another rapid-fire weapon had hit Australia.

The Pardus LAX is being billed as "the new entrant" in the lever-action market, which with a shorter lever action, can be reloaded even more quickly than the "fast and furious" Adler A110 which attracted controversy last year.

The development comes as a ban on the Adler that can shoot eight shots in as many seconds will expire in a month, and after more than 7000 of a modified version that holds five rounds were sold in Australia in just six months.

"The minister (Mr Keenan) should act quickly and swiftly by making all lever-action shotguns into Category C," Gun Control Australia said in a statement on Monday, warning too that "the modern lever-action shotgun has found a new market here in Australia".

"Since the federal government approved the importation of the Adler A110 we are seeing firearm companies competing for this new firearms market, trying to out do each other in terms of capacity and design."

The issues of gun regulation and counter-terrorism are set to be discussed at a national policing summit in Sydney this week.

The Pardus, meanwhile, is already attracting attention on gun websites in Australia, including so-called "prepper" sites frequented by people who believe a catastrophic disaster is imminent.

Offering condolences to Americans following the worst mass shooting in US history, Prime Minister Malcolm Turnbull on Monday said Australia was "ever-vigilant, we have strong gun laws in this country thanks to the work of John Howard years ago".

At least 50 people were killed and more than 50 more injured when Omar Mateen, who had pledged allegiance to Islamic State, opened fire in a crowded gay nightclub in Orlando, Florida at the weekend.

"Our security and police forces are vigilant in ensuring that we are protected against this type of extremism, this type of violence," Mr Turnbull said.

"We are rigorous in our efforts to ensure that guns are not illegally imported into Australia and we enforce the gun laws rigorously across the country."

Former prime minister John Howard argues, however, that current gun laws are inadequate.

"I'm not going to preach at the state government over this, they have to make a judgment about it," he said in April.

"But I'm wholly against any watering down of the existing laws, and I would encourage sensible strengthening of the existing laws."

Mr Keenan will give the keynote address at the national policing summit.

The summit will also discuss gun regulation, and in particular lever action shotguns and semi-automatic handguns, as well as a review of firearms ownership.