Igor

Just from my perspective / what I have seen personally, on youtube, in DVD's.

I am not saying this is definitive but Europeans seem to
have slings on their rifles. Maybe it is because of how they hunt, be it going from stand to stand on a driven hunt
or carrying gear to a high stand or climbing hills.

I just did a quick google and youtube on European Hunters and most had slings on rifles. One even had a sling on a shotgun !!!

I don't hunt with a sling on my gun but I always carry one
in case I or someone has to carry another person out of the bush due to injury. It is hard to do without slinging a rifle.

Anyway, that is my take on it.