I find it funny how many people don't understand the basics. But you know what, let him order internationally, and let him suffer for it. He had fair warning.
Just to keep poking the dead horse; Get age verified when you're 18. You won't find that gun anywhere in Canada outside of the classifieds. Do not order internationally, for very obvious reasons.
For anyone looking for age verification in the Windsor region: Unfortunately, I will only be verifying people at games, I am currently unable to run around and setup meetings.