LOL.
Not a gun but a mate of mine went to Canada on one of those Survival course holidays a couple of years ago. He took with him a rather large Bowie knife. At UK customs there was a bit of a panic but he was eventually allowed to take it in hold luggage.

On arrival in Canada, he declared it and was asked to open his bag by a rather nice little customs lady. She picked up the knife and , laughing, said " That's not a knife! it's the kinda thing we give our kids to play with. Thank you for declaring it but I've got better things to do so pack your bags and move along. Have a nice vacation sir."

How much embellishment there is, I don't know. But it struck me as funny