This young man is Jørgen Christensen, founder of www.Schultz-LarsenRifleClub.dk shooting at Fåvang in Norway in 1957. This particular Krag-Jørgensen was borrowed and is a hunting rifle chambered in 9.3 x62 which is not so far off a 30-06 case wise but with a somewhat heavier bullet.
Jørgen tells me the majority of hunters used the Krag-Jørgensen rifles, usually in 6,5x55SE converted to single shot. The reason for the single shot modification is they were hunting Reindeer which tend to herd together so the single shot meant reloading took longer and gave the Reindeer a more sporting chance.
All of the people in this picture are Reindeer hunters and they would have to attend a compulsory shooting test once a year to make sure they could use the rifles accurately and safely. The tests took place at 100/200/300m.
Jørgen tells me the same rifles were used for Moose/Elk however they would be hunted with a full magazine.