You're welcome. Air Canada will get it all there, just sillier than other airlines. Any hard case should be fine. If you can takedown your rifle and pack in a smaller (less rifle looking case) thats better, but not really necessary.
Most hard cases are sufficiently sturdy. If it gets mishandled badly, there is no case (or the rifle inside) that is going to stand up to severe abuse, but I've never had any issues. The good news is that your rifle case will be tagged differently and will be handled separately, so I think that might(?) give it a better chance of safe arrival.
By the way, when you land in Auckland, after you pick up your bags (including rifle) and before you leave the baggage claim area, there is a tiny police booth along the wall, that is usually unmanned. There is a phone on the wall, pick it up and tell whomever answers where you are and you'd like to see a police officer about importing in a rifle to hunt. Then stand there until a friendly officer shows up, looks you over, examines the gun, takes $25 NZD cash (don't forget to get the cash before you board in Canada!), and you're on your way.
The game animals in NZ (Red Stag, Tahr, Chamois, Fallow Deer, wild pig, etc) are all introduced species (over the past 150 years or longer?) and are considered feral invasive species, and even most of the lunatic left supports hunting them, I think because they compete for habitat with native wildlife. They are all well established and there are no predators. There is no specified hunting season, no bag limits, or any other typical restrictions, because there are just so many animals. The challenge to hunt them, is the country is very rugged and the good animals are typically in remote areas that are difficult or time consuming to get to, and require physical stamina to be successful (unless you are old and fat and can afford to rent a helicopter, or you want to shoot an animal in a fenced off 'cage', neither of which appeals to me, and both those options, while available, are very expensive). I trained for a year specifically for a NZ hunt and it really paid off. Your daughter might be able to arrange and easier hunt, as she like knows locals and that can be very helpful. Have Fun!
