I'm heading to Canada for the first time and I recently flew with my rifle back to Idaho. The wt limit for the ammo is 11 pounds.
The airlines are the ones that make up the rules on how to travel with the ammo. In my case they had to be in a marked container designed for ammo and could not be with my rifle. Read the TSA website, it spells this out very clearly there. Some airlines don't even know their own rules. I printed out the airlines rules and had to show them to the person checking me in. After discussing with a supervisor they agreed I was correct about the ammo
DCN is not correct about the locks. The locks on a case carrying a rifle have to be regular locks. Not the TSA designed locks. You may slip by with TSA locks but the TSA website is very clear about this as well. They have to be regular locks and you better put 2 on the case. If the inspector can get into the case, even a little at one of the ends of the case they will require another lock and I've heard they aren't cheap at the airport. For the ammo you can have a regular TSA lock on your luggage that has it.
Bring a cell phone and leave it on until the plane leaves. You will have to fill out a couple of cards to go with the rifle and ammo. If the TSA wants into the rifle case again they will give you a call.
If you belong to SCI you can purchase extra gun insurance at a really good price. If you are concerned about damage or loss of your rifle it's cheap insurance that a lot of people recommend.
Last but not least enjoy the hunt and get a big one.