'Partsgone' - Your Norwegian Krag appears to be a "Carbine M-1897 for Mountain Artillery and Royal Engineers".

In 1900 carbines were built to this classification from serial # 3,131 to 4,696.

The Mountain Artillery and Royal Engineer carbine has the rear 'Sling-Stud' placed 3.94 inches in front of the butt-plate. (Otherwise the guns are identical to the M-1895 Cavalry Carbine).

Both carbine models have a solid steel butt-plate, measuring 4.29" X 1.50", without a 'butt trap-door'.