Winston Peters says there are plenty of sound reasons for schools to allow children to handle guns, adding that in the "old days" it was part of country life.
Education Minister Nikki Kaye is calling for guidelines for guns in schools after it emerged children aged nine to 13 were handling unloaded assault rifles at a Manawatu school during an Army roadshow.
"In the past there would have been situations where it's been okay under the law, but I think it's a really important area where we need to give greater guidance," she told Newshub.
Mr Peters suggested the minister defer to the experts' guidelines.
"Why don't they just use the experts? Namely the army or the police? I mean they wouldn't know one end of a gun from the other," he said.
While explaining the possum bounty scheme of the 1950s that gave rewards for the pests' ears and fur, the New Zealand First leader took aim at a Newshub reporter.
"In the old days a lot of children made a lot of money when there was a bounty on, for example, possums, where they're out there shooting and making... Don't laugh, you're obviously a city girl, you don't understand," he said.
Mr Peters says country people used to pay for school fees with money earned by shooting possums.
He also squeezed in a jab at the Department of Conservation's use of 1080 to control possums.
"There were a whole lot of kids out in the countryside in a former time, catching them rather than poisoning the whole environment with 1080, was what they did."
He says whether guns are allowed in schools is dependent on the circumstances.
"If you are teaching country kids at a certain age how to use a gun safely, there may be a reason for that, and there could be six or seven other sound reasons."
Labour's education spokesman Chris Hipkins is strongly opposed to guns in schools and welcomes the call for guidelines.
"I don't think that semi-automatic weapons should be in schools full stop," he said.