A gun owners' group says it fears a planned firearms registry will be a "juicy target" for criminals after multiple recent Government data breaches.

But the Police Association said the Council of Licenced Firearms Owners (COLFO) was scaremongering, and predictions of rampant firearm owner civil disobedience were ridiculous. 

Some firearm owners were probably already hiding guns, fearing the register would endanger their loved ones, COLFO said on Monday.

The register was among the second wave of proposed gun law reforms initiated after the March 15 Christchurch mosque shootings.

COLFO cited concerns after multiple data bungles and breaches in the health sector, Treasury, and Commerce Commission.

"The registry will present a serious issue of data security," COLFO said in a submission on the Arms Legislation Bill circulated on Monday afternoon.

The group said anecdotal evidence suggested some "otherwise deeply responsible people" were hiding guns.

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To avoid "making their family homes a special target" those people would not register, COLFO added.

Stuff has reported the proposed register would be an online, self-service entity, akin to NZ Transport Agency's motor vehicle register.

Prime Minister Jacinda Ardern announced gun law overhaul details in July. Police Minister Stuart Nash said the register would roll out over five years.

Nicole McKee of COLFO's Fair and Reasonable Campaign told Stuff the registry would be of "no benefit to public safety".

She said proposed reforms had no specified penalties for unauthorised registry access. 

"We are starting to hear from more and more people that if registration goes across they will not be complying."

She said COLFO did not endorse law-breaking but recent public data debacles undermined faith in Government record-keeping.

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In 2017, under the previous Government, then-Police Minister Paula Bennett said McKee would provide independent advice on a Select Committee report into illegal firearm use as MPs reviewed gun control.

That June, the Government said registration of all firearms owned by firearm licence holders would be "very expensive", resource-intensive and probably inaccurate.

McKee on Monday said she didn't believe she was "that influential" in the 2017 discussions but repeatedly sought to prevent governments passing laws which might backfire.

"One of the things we've pointed out is that we didn't see anything in the second tranche that would've prevented Christchurch from happening."

Police Association president Chris Cahill said data security was crucial but he knew of no cases where external hackers breached existing police firearm registers.

Collectors, pistol licence holders and former E category owners were registered.

Cahill said the association was "fully supportive" of calls to penalise unauthorised registry access, though several existing laws covered similar offences.

He said COLFO 's submission seemed designed to convince gun owners "the world was about to end" but firearm owners would not succumb to mass panic.

"They register their cars. They register their pets. They will register their guns, because they're good people."

He said reforms pivoted on the register, and a similar Australian model had been beneficial.

Nash said through a press secretary the select committee was the appropriate forum for "the variety of perspectives on tighter gun laws" and he wouldn't comment on individual submissions.

Submissions on the Arms Legislation Bill close on October 23.

LAW CHANGES PROPOSED:
* New online self-service firearms registry
* Gun license periods halved from 10 years to 5.
* Warning system to show if an owner is a "a fit and proper person"
* Barring visitors to NZ from buying guns
* Registering NZ's estimated 260 gun clubs

LAW CHANGES ALREADY PASSED:
* Military style semi-automatics and assault rifles banned
* Semi-automatics like .22 calibres and shotguns with limited ammunition capacity exempted
* Tighter penalties for possessing and importing banned ammunition
* Gun buyback and amnesty scheme initiated
* Ban parts, magazines and ammunition used to assemble banned firearms