Light caliber doubles are popular in Europe.
We are hunting often at short range ( inside 100 yards ), and often in wood.
The double are instinctive, and allowed quick second shot if necessary.
Caliber like 7X57mmR, 8X57mmR, 9,3X74mmR are often encountered. They are enough caliber for european games, the biggest being big deers and wold boars. And mixted barrel ( one shotgun and one rifled barrel ) are an interesting option, too, allowing to hunt bird and big game with one gun.
Many hunters are using only side-by-side or over-and-under shotguns. Birdshot for birds and slugs ( Brenneke, Foster or Sauvestre most of the time ) for big game.