It is funny to read literature (fiction and non-fiction). IIRC Dickens has an Englishman put a revolver in his pocket and proceed to travel to “The COntinent” and on to Egypt with that loaded revolver and is not even challenged by customs at any point of entry. Fascinating. What was different about those folks? That they could carry loaded revolvers anywhere and not shoot up schools or train stations?
Many European countries did have severe firearms restrictions. But these sometimes excluded foreigners or travelers passing through.
Spain for one had pretty much blanket restrictions since the Middle ages. Britain had none at all. Others varied, mostly tending to no restrictions.