Turns out that gun owners aren’t as stupid as Leftists think! To date, only 700 of an estimated 3 million guns have been turned in, as the new authoritarian law demands.
New Zealand doesn't require gun registration, so there's no way for them to enforce the law without going house-to-house, which would be a major violation of people's rights.
https://reason.com/2019/07/08/noncompliance-kneecaps-new-zealands-gun-control-scheme/