The game could be whitetails in the East, elk in the West, or anything from duiker to eland in Africa; these five cartridges have been there and done that.
Time will tell if the AR design will gain mainstream acceptance with American hunters, but this rifle has certainly opened a big door to that possibility.
Hunting common eiders is not for everyone. Their location, along with the equipment required and the difficult conditions, limit enthusiasts to a dedicated few.