Armed police will provide tight security for day one of the Government's controversial gun buyback scheme in Christchurch starting tomorrow.

Gun owners going to cash-in their now-illegal firearms – or hand them over anonymously and without question during the amnesty option – can expect armed officers at the collection event at Riccarton Park Racecourse.

More than 900 Cantabrians have made online notifications to police already, amounting to 1415 firearms, police revealed at a preview media event this afternoon.

It's not clear how many guns will be handed in between 10am and 3pm tomorrow and Sunday.

The Government's gun buyback and amnesty scheme follows the gun law reform in April that banned most military-style semi-automatics (MSSA) and associated components in response to the Christchurch terror attack that killed 51 people.

Police released an extensive list of guns, each with a price for poor condition (25 per cent of the base price), average condition (70 per cent of the base price), and new or near-new condition (95 per cent of the base price).

The list covers more than 300 guns and also includes gun parts - including magazines, silencers, open sights and custom triggers - with a different price setting: 70 per cent of the base price for new or used, and 25 per cent of the base price for poor condition.

The prices were put together by consultancy firm KPMG, which consulted widely and also held a workshop with firearms experts.

The gun buyback scheme has been criticised by some gun owners.

Gun lobby group, the Council of Licenced Firearms Owners (Colfo) has joined forces with Gun City owner David Tipple to fight the Government's gun law reforms and its buy-back prices.

It has launched the "Fair & Reasonable Campaign" which, according to its website, is aiming for hundreds and thousands of dollars to take court action "seeking full compensation for the loss of your hobby, sport and lifestyle".

Police say that local collection events are the preferred option of safely collecting firearms and parts during the buy-back period and, with more than 250 already planned in cities, towns, and rural communities across the country.

"We want to make it as easy as we can for people to do the right thing and hand-in their firearms," Deputy Commissioner Mike Clement said earlier.

"As police prepare for these collections events, we can assure the public that these events are well planned with strong safety measures in place that will allow people to hand in their firearms in an efficient manner."

Today Canterbury District Commander Mike Johnson said it was appropriate that the first collection event is being held in Christchurch where the March 15 terror attacks happened 17 weeks ago.

He admitted that the buyback scheme has been a "polarising topic" but the legislation and its ramifications are very clear.

"There's been a law change and this is about law-abiding New Zealanders who want to engage in the process, and those 903 people have engaged in the process already," Johnson said.

He encouraged people prior to arriving at the collection point to complete the online notification form to save time, otherwise it can be done at computers on site.

There will be "a number of security measures" tomorrow, police say, including armed staff.

Johnson said police don't anticipate any trouble but they want to make the event safe for both the public and police staff.

He asked that they're brought to the collection point "in a safe condition", preferably in a bag or appropriate case.

When the firearms are brought in, they will be "cleared" using a bullet-catcher machine.

A yellow flag will be attached to them and indicate they have been safely cleared.

People using the buy-back scheme will need to bring with them a photo ID, bank account number, firearms licence if applicable, online notification number, and firearms/parts cleared of ammunition.

Once the firearms are handed over, they will be made "inoperable" as soon as possible, Johnson said.

People using the amnesty scheme will simply hand over the weapons and walk out – no questions asked, no names given or ID provided.

Police encourages any person now in possession of a prohibited item to safely secure it and notify Police by completing the online form or calling 0800 311 311.