A gun policy expert says New Zealand lobbyists have a history of swaying the Government.
Philip Alpers, the founder of gun control website gunpolicy.org, says in recent history, the gun lobby has watered down every single recommendation on gun control in New Zealand.
"As a result, all the significant suggestions that have been made in the past 22 years have not been enacted."
The classic reaction from gun lobbyists when there is talk of gun reform is to implore the Government to resist having a 'knee-jerk' reaction, Alpers says.
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This delays action and, in the meantime, gun enthusiasts will write letters to the editor and to local MPs to dilute any real change.
"In New Zealand, an MP can be swayed by eight or 10 letters on a single topic because that constitutes a flood of letters," he says.
"The gun lobby has this outsize influence because they can persuade MPs and others that they're much more numerous than they actually are."
At the moment in New Zealand, there is a loophole where someone can convert a legal A-class weapon into an illegal E-class weapon.
The man charged over the Christchurch terrorist attack had two semi-automatic rifles as well as three other firearms, all held legally on his entry-level category-A firearms licence, obtained in December 2017. Allegedly, the semi-automatic rifles were modified from a seven-shot magazine, to a 30-shot magazine.
"Thirty-shot magazines are not regulated in New Zealand," Alpers says.
"You can still buy those magazines all across the country."
The weapons of choice for mass killers, Alpers says, are military-style semi-automatic 'assault' weapons.
In the wake of Port Arthur, the Australian Government banned all semi-automatic rifles - 700,000 of them, and destroyed them, Alpers says.
"They took them right out of circulation and that is the reason that this alleged killer was not able to do what he did in Australia.
"You have to ask, did he come to New Zealand because of that loophole?"
Following the destruction of 700,000 semi-automatics in Australia, the risk of dying by gunshot dropped by more than 50 percent.
"Before 1996 Port Aurthur there had been 13 massacres [in Australia]."
After those laws, not a single mass shooting happened until last year when there a licensed shooter killed his family of six in a domestic tragedy, Alpers says.
"Most people don't realise. Most victims of mass shootings in Australia and New Zealand have been shot by licensed sporting shooters wielding lawfully-held firearms.
"In mass shootings, at least, it is the licensed shooters who kill most people," Alpers says.