Gun owners want moves to crack down on their hobby to be delayed until after a "discussion" has been had.
Prime Minister Jacinda Ardern has promised law changes are on the way, following Friday's horrific attack on two mosques in Christchurch that left 50 dead.
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Semi-automatic rifles are expected to be the focus as Cabinet meets on Monday, with Ardern saying existing work on New Zealand's gun laws to be reworked and "expedited".
It took Australia only 12 days to outlaw semi-automatic rifles and shotguns after the 1996 Port Arthur massacre, in which 35 people were killed.
But the Council of Licenced Firearms Owners wants a discussion first.
"It's very easy to say 'it's this type of firearm', but to actually ban a type of firearm, is that going to be effective in stopping this from happening again? Let's have a look at the bigger picture," spokesperson Nicole McKee told The AM Show on Monday.
Changes "need to be effective - not kneejerk", she said.
"New Zealand firearms licence owners are not the terrorists. We are legitimate owners. But something has gone wrong here, we acknowledge that. We do acknowledge there needs to be a law change, we do acknowledge that there needs to maybe be an administrative process change, and we'd like to be a part of that. But it needs a thorough investigation."
The Police Association says the discussion, if there is one, should be "short and swift".
"There is no place in the upcoming debate for the radical gun lobby which has made its presence felt in previous attempts to make our country safer," said president Chris Cahill.
A cross-party select committee recommended 20 changes in 2017, only seven of which were accepted by then-Police Minister Paula Bennett. Rejected recommendations included the creation of a new restricted category of weapons that would have included the kinds of weapons suspect Brenton Tarrant allegedly wielded during the attack, and a requirement for police to record firearm serial numbers upon renewal of licence or inspection of premises.
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Ms McKee said the gun lobby has "worked well with politicians and with police on doing improvements to our legislation" in the past, and wanted a say in whatever changes the Government is considering now.
"There are uses, legitimate uses, by legal owners here in New Zealand. They include sporting, they include business, and they include farming. So there is reason for having them. The guys who do have them legally, are using them legally. So let's have a discussion."
National leader Simon Bridges said changes have to be made, now that "everything has changed" - but is also in favour of taking a considered approach.
"We want to be constructive partners in all of this. I don't know what the Prime Minister and the Government is proposing. I want to see that... I think there is a wider - I hate the word - conversation to be had, and reform potentially."
One of his MPs, former Minister of Defence Gerry Brownlee, says in the meantime sales should be halted immediately.
"We can do that in Parliament tomorrow afternoon," he told The AM Show.
He condemned gun fans rushing out to buy new weapons in the wake of the attack, saying no one was going to be "sympathetic" if the Government puts an Australian-style ban in place and they're forced to return them.
He called the panic-buying "incredibly insensitive".