In Canada’s defense, that in significant part, handguns. If you keep a long gun with you, as long as it doesn’t hit their 10,000 J (7375 ft-lbs) muzzle energy limit — and if it’s in your glovebox, I assume that whatever you have isn’t doing that — and doesn’t hit their specific restrictions on upper receivers, you’re probably okay.

A NATO 5.56 mm rifle round looks like it has a muzzle energy of about 1.8 kJ.

That’d let you carry an elephant gun.

If you want a semi-auto rifle…goes looking

gunsamerica.com/digest/big-horn-armory-ar500/

I imagine that one of those would be okay. Looks like the ammunition is sold in Canada.