Here’s a relevant post from another thread.
Short version: Gun laws in Canada have been very strict and very effective for many decades and are about to get even stronger. Age limits to above 18 are not among either existing laws or new proposals. They’re very unlikely to do anything useful in a society already saturated with guns and seems to be just another feel-good smokescreen for “gun control” while actually accomplishing little or nothing. Pretty damn hypocritical, too, when you consider that 18 was the age of draft eligibility to be sent to Vietnam to kill and possibly to be killed.