My last six hunting trips were to Edmonton, Alberta, originating in Boston, and flying a variety of domestic airlines, and Air Canada. The rifle was inspected at Boston, and an inspection slip placed in the gun case. The case can then be locked. Ammo was not allowed to be in the same case as the rifle. They specifically checked for this. Upon arrival in Edmonton they may ask to open the rifle case but they have an xRay machine and typically do not ask to open the case. The other luggage, including the one with he ammo packed should have TSA locks. My luggage has been inspected about half the time. The TSA lock has an indicator that let's you know they opened your luggage. One more item. If you handle your rifle, ammo, or store your case where you keep rifle powder be sure to wipe your equipment down with Windex or other cleaner. Particularly the handles. Also your hands. I have had the explosive test machines pick up the powder residue at the airport when they swab the handles of your luggage. They're very sensitive nitrogen detectors. This will cost you an hour with security agents and
their sniff dogs.