Around 3000 firearms have been marked for collection in the Government's buyback scheme and are not eligible for compensation, Police Minister Stuart Nash says.
And police have seized an additional 1300 unlawful guns since March, many from gangs and people without firearms licences.
Meanwhile Police Commissioner Mike Bush has indicated that he will not be revisiting the pricing list for the buyback scheme, which has been decried by some in the firearms community as unfair and in need an overhaul.
Nash revealed the latest numbers while attending a police open day for what the collection process should look like at Trentham racecourse in Upper Hutt today.
Deputy Police Commissioner Mike Clement said that safety was the main priority, and firearms would be crunched under a hydraulic press after being collected.
People eligible for compensation would be paid within 10 working days, but people could hand in any firearms under the amnesty and they won't be prosecuted or have to provide any personal details.
Clement said police had no real gauge on how many firearms would be surrendered at the collection events, but there was a "surge" plan whereby extra police officers could be on the scene for any reason.
More than 250 collection events have been organised for the next three months for people to hand in their firearms that were made illegal by a new law, which banned most military style semi-automatic firearms and associated parts.
The Kiwi Party challenged the validity of the law in the High Court in an effort to push the law out until after the 2020 election, but the court tossed it out.
The first collection event will be on July 13 at Riccarton Racecourse in Christchurch. More will be announced for the last three months of the amnesty, which runs until December 20.
Under the buyback scheme, only firearms obtained legally by someone with a valid firearms licence will be compensated.
Nash said more than 840 firearms had already been handed to police.
"Owners have declared their intention to surrender almost 8000 further firearms, via online forms. Around 3000 of these weapons are not for compensation but are being surrendered as part of the amnesty.
"In addition more than 1300 unlawful firearms have been seized by Police during enforcement operations since March. Many of these weapons are from gangs and offenders without firearms licences."
The scheme has angered some in the firearms community, and the Council of Licenced Firearms Owners is gathering funds to mount a legal challenge.
John Herbert, who owns the online store New Zealand Repeating Arms and was part of the expert group that was consulted for the buyback scheme, said the pricing list was a "complete joke" in some cases and owners of collectables would feel ripped off.
Bush is the only person with the legal authority to amend the price list, but in a statement, police did not answer whether he had any appetite to do so.
The statement only referred to changes to the list for items that were not currently on it.
"Once police is made aware a firearm is not on the price list and this is confirmed, a firearm will be entered into the system and price investigation undertaken. Should the investigation be successful, the firearm will be added to the price list, which will be updated and notified in the Gazette and online."
Nash has also pushed back on any suggestion that the price list should be changed, saying during Question Time last week that consultancy firm KPMG had consulted widely including with farmers, hunters, dealers, valuers, auctioneers, collectors, and gun clubs.
"Thousands of people are not saying they feel ripped off. Our feedback is that 80 per cent of all phone calls are positive; only about 5 per cent are negative."
He asked people intending to hand in their firearms at collection events to complete details on the police website.
"Firearms owners should turn up with their reference number, bank account details, firearms licence and photo ID. The firearm should be cleared of ammunition and in a safe carry bag."