It came after the killing of 51 worshipppers at two mosques during Friday prayers in Christchurch last March.
Fifty-thousand guns have been handed in to authorities in New Zealand during a six-month buy-back scheme.
It came after a ban on assault weapons following the killing of 51 worshippers at two mosques during Friday prayers in Christchurch last March.
A small group of protesters gathered outside a police station in the city on Saturday, some saying the ban doesn't cover the right guns.
But New Zealand's legislators were emphatic in passing the law; only one MP voted against it.
The country's Police Minister Stuart Nash said about 32,000 residents handed in their weapons when the buyback ended at midnight on Friday.
Provisional figures also indicated that 51,000 guns in total were handed in during the scheme.
Another 5,000 guns were also given up by as part of a parallel amnesty in which owners could hand over any type of firearm without any questions being asked but without getting compensated.
Owners also modified another 2,700 guns to make them legally compliant, while police said they had seized a further 1,800 guns from gangs since March and are in the process of collecting another 1,600 guns from gun dealers.
Lawmakers are now considering further restrictions, including creating a register to track all guns.