'Mike W' - Welcome to the KCA Forum.

It sounds like you may have a 'cut-down' model 1894 Norwegian service rifle, that was made in 1910 and equipped for telescopic sight.

The original barrel length should be approximately 29.5 inches. Your barrel has probably been shortened, unofficially, for Hunting.

Sigurd Halverson wrote the chapter on Norwegian Arms in William Bropy's book, "The Krag Rifle".
On page 139, Halverson commented:

"In 1910, in the army serial range 89,601 to 90,600, a thousand rifles were made with telescopes. The 4X Maal telescopic sight was offset to the left, in an adjustable mount on the left side of the rifle. For transportation, the scope and mount were contained in a wooden case.".

A few years back a gentleman, (who's name I cannot recall), did a beautiful restoration of a cut-down Norwegian 'Sniper-Rifle' and allowed us to post his pictures on the KCA Forum.
(A search of past pages should contain this generously shared information).

To undertake such a restoration requires considerable knowledge, dedication, skill, and ultra rare parts!
BTW - the Norwegian barrels have a left-hand thread!

If your action and barrel are in sound shape, it should be safe to fire standard loadings of commercial 6.5X55mm Swedish Mauser ammo. Afterward, save your Brass and reload with 'starting' loads.

Photo of Norwegian action with provision for military scope mount:

Interesting to see that barrel. Extractor cut is much larger for a much larger extractor. Besides being left handed, the thread profile appears to be a truncated "V" style instead of square threads on the US Krag.