Ammunition wholesalers in Australia are expecting one of the biggest supply shortages in recent history with American civilians purchasing arms at record speed.

Scrutiny of gun laws in the United States is thought to have sparked the gun sales boom, with the flow-on effects expected to reach Australian shores within weeks.

Some of the most popular bullets will soon be unavailable in Australia and New Zealand and will not be restocked for about another six months.

Firearm importers in Australia are being told to brace for supplies to run extremely thin or completely dry within weeks.

Importer Jade Cleaver says he has been buying more than usual in anticipation.

"We've been stockpiling ammunition in a sense so we don't run out," he said.

"Basically the American community is consuming the ammunition and the Ammunition manufacturers can't keep up."

Australia's eight main firearm wholesalers source about 80 per cent of their stock from the United States.

Mr Cleaver says producers are operating around the clock in a bid to keep up with demand.

"There's only so much they can produce," he said.

"There's only 24 hours in a day and putting capital out for more machines.

"I know the products that we import into Australia; they've gone from running 12-hour shifts at their companies to running 24 hours."

Gun ammo running out in Australia as US citizens buy big - ABC News (Australian Broadcasting Corporation)