An anti-gun lobby group is rueing what it says is a "lost opportunity" after the Tasmanian Government rejected a move to restrict the use of a controversial shotgun in the state.

The A110 uses a lever action to load cartridges into the barrel.

But unlike most other lever action shotguns, it has a magazine capacity of seven rounds with another round in the barrel, meaning it can fire up to eight shots in rapid succession.

The Tasmanian Greens want to amend the firearms act to restrict the use and sale of the gun to users with "demonstrated need" like primary producers.

Gun Control Australia's Roland Browne is warning of the dangers of not acting.

"This is a rapid fire gun, it's the sort of thing that's going to be used in mass shootings, no question about it," Mr Browne said.

"This is a lost opportunity for this Liberal Party Government and I would like to see them reconsider."

Police Minister Rene Hidding said the Government would not be supporting the Greens' move to restrict use.

"All states and territories agreed that we would be together on key matters such as the categorisation of firearms," he said.

"This bill would tend to take us outside of the national framework, so we are not having any part of it.

"The underlying concerns that are expressed by the Greens obviously we will deal with, with respect. We would wish to do so in a national framework."

Port Arthur anniversary 'a time to pull together'

Mr Browne said the upcoming anniversary of the Port Arthur massacre strengthened the case for restricting the gun's use.

"The 20th anniversary of the Port Arthur shootings is next year, and I think it's a time for Australia to pull together," he said.

"We want to make sure that an event like that is never repeated again."

Minister Hidding said progress was being made on moves nationally to achieve what the Tasmanian Greens were seeking.

"While they [the Greens] were working on that document, the ministers of all states and jurisdictions were considering exactly this and have agreed to resolve it by next July," he said.

But Mr Browne is warning July is too late, and the potential cost of a taxpayer-funded buyback scheme is growing.

"It's a lame excuse to say they're waiting for some sort of national decision, there's every reason for Tasmania to move right away," he said.

"As the guns keep getting sold across the community, the later the governments leave it, the more expensive will be the buyback.

"The Government should act now, they should avoid the massive costs of a buyback and they should avoid the mass shooting now."