No gun registry means unknown number of guns out there - Stuart Nash

Stuart Nash said it's difficult to set a budget for the buyback scheme because they do not know how many guns are out there. - Photo: RNZ / Dom Thomas

The Police Minister says the first ever firearms collection event in Christchurch over the weekend was a huge success.

But Stuart Nash had concerns about whether the participation reflected the number of weapons in the region.

More than 378 people handed in 542 guns and there was a mixed reaction from firearms owners.

The total compensation cost amounted to $1,022,599.

For many gun owners it was a bittersweet moment handing over guns that were outlawed in the wake of the Christchurch mosque attacks

James Agnew, one of hundreds of gun owners who showed up to the gun amnesty in Christchurch, reflected how many were feeling.

"A bit disappointed yeah, it would be pretty hard for someone to say they aren't disappointed because a lot of people just enjoy it in general and they just feel a bit discriminated [against] and the way it's betrayed that we are the bad guys," Mr Agnew said.

Others at the firearms collection at Riccarton Racecourse said the process was simple, but were steadfast in disappointment.

"I'm sad, but hey - I'm a big boy so I will live with it, it's real sad that this had to occur, but it is what it is.

"They make the rules, we just abide by them."

Dozens of gun owners handed in their weapons, which have been made illegal in the wake of the mosque shootings.

Dozens of gun owners handed in their weapons in Christchurch. Photo: RNZ / Simon Rogers

Despite 900 firearms owners registering online for the Canterbury buyback scheme, only half that number took part.

Canterbury's acting district commander Mike Johnson said there was still plenty of time left for those who missed the event.

"The other options for hand back are into a police station, we are arranging a dealer hand in which will be advertised as soon as it's finalised. The other is, if you have 10 or more firearms, if you register online we will come to you," Mr Johnson said.

Police Minister Stuart Nash said he suspected there were more people in the area who had not registered online at all.

He said it was impossible to say whether the numbers of guns handed in at the weekend had significantly reduced the number of illegal weapons in the Christchurch region.

Mr Nash thought the event was a great success, but without a registry, he said they had no idea how many guns were out there.

"It's very difficult to know if 900 is a lot, or 900 is not many, because you didn't need to record if you were buying one of these banned firearms, you didn't need to have a special endorsement on your firearms licence.

"So in terms of the sort of gun the terrorist used to kill people on March 15, we have no idea whatsoever," Mr Nash said.

The secretary of the Council of Licensed Firearms Owners, Nicole McKee, said communication and direct contact as well as clarity around compensation is crucial to make the process fair for all firearms owners.

"This is not just about semi-automatics, it's MMSA's [military-style semi-automatic] - and then of course addressing the compensation issue. There are a number of firearms that are missing from that list and there are a huge array of parts and accessories that are not on that list that cannot be used by other types of firearms," she said.

The government has budgeted $208 million for the buyback scheme following the law reform.

But Ms McKee said she had a message for the government.

"Get your hands out of your pockets and start showing these people you are going to be fair, and you are going to be reasonable when confiscating their private property."

She said it was far more likely to cost close to $1 billion for 250,000 firearms.

Stuart Nash said because they do not know how many guns are out there that need to be handed in, it was hard to put an accurate figure on the budget required.

"It's not until we really get into the scheme, that we will have a better idea if we are going to need more money, or if we have got it about right.

"But it really is very difficult to even put a forecast in place until we have a better understanding of how many weapons are out there.

"We simply have no idea whatsoever. We are flying blind but it is an educated guess and we will see how close we come," Mr Nash said.

There are still another 258 events to be rolled out across the country, he said.

There will be events in each police district from next weekend until 20 December when the amnesty period ends.