In order to possess and transport a rilfe or other firearm in New Zealand you will need  to be granted a Firearms Licence from the New Zealand Police.

Licences for New Zealand nationals are issued at the sole discretion of the NZ Police, and are usually valid for 10 years. To be granted a licence, you must:

• Be over 16;
• Be a "fit and proper person" to possess and use firearms;
• Attend a safety lecture given by a volunteer from the New Zealand Mountain Safety Council;
• Pass a written test based on the material in the Arms Code;
• Undergo an interview with a police officer who will inspect your security provisions for firearms and ammunition storage;
• Provide two referees to vouch for you (they must be over 20, one of them a relative);
• Provide a photo and pay the fee (currently NZD$126.50 as at January 2011).

You can get full details from the firearms section of the NZ Police Website.