The number handed in is still only a tiny proportion of guns in the country, estimated to be between 1.2 and 1.5 million.
"[My daughter is] called Charlotte. She's about the same age as you," the prince said to 5-year-old Alen Alsati.
The country is set to change its gun laws within days of an attack that claimed the lives of 50 people.
"There was a want to receive the dead immediately and start the grieving process...but they realize that this is not like any other incident," said one family member.
"We would like to remind people that it is an offense to distribute or possess an objectionable publication," New Zealand police warned in a statement.
"Mum, there's someone come into the mosque and he's shooting us," the 16-year-old said. Then came the shot.
The prime minister of New Zealand called the attack "an extraordinary act of unprecedented violence."
"This is it, wish us luck! (My partner and I cycled because there wasn't enough room in the car for the support crew ... but it also put me in the best possible mood!)," Julie Anne Genter wrote in an Instagram post.
"It's really heartening to be spending the first week back on deck on issues that really matter to me," Ardern said.
The country's Deputy Prime Minister Winston Peters will take over.
The former Democratic presidential candidate met with Prime Minister Jacinda Ardern before giving a talk at a sold-out event with a minimum ticket price of $130.