You got a very nice M1912/16. Early serial of those made in 1916. It miss the rear sling swivel, that is reason of the  screwhole at rear. Got the reinforcement band in front, mounted on those with the 1912 noseband with the 1916 reinforcement band. As early serial, it has the stock that do not flush the reinforcement band. Later 1912/16 got stock so it flush the outside of the reinforecement band, as it does on those 1912/18 that got the complete noseband with the integreated clamping.
Some historical detail, by serial identified as located at IR8 in 1940 (Infantery regiment 8), Evjemoen. Evjemoen were bombed April 11 1940, but your krag seem to survived. There were some fighting between IR8 and the germans in 1940, but with an aonther divition of IR 8 then those located at Evjemoen.