You know ... this is the same thing that every forum says ... do your research. You won't be spoon fed answers. They're all out there already. Get age verified and learn just how many things you can buy new or used. There's a whole other world out there. It will also allow you to search in the AV section of this forum and get proper answers.
That being said, that gun shouldn't have a problem, but if CBSA is having a bad day .... Better by far to get verified (look it up, there are people in Montreal) and then spend your money inside the country where this isn't a problem and you don't risk losing it.
"As technology reduces the weight of weapons, ammunition and equipment, infanteers reap no benefit; they are merely required to carry more."
- Lew MacKenzie