'Concretus' - Thanks for your additional pictures. Your barrel with the "P" (proof) marking is a Krag barrel.

I don't know why your rear-sight is setting so low in its hand-guard.

Attached, is a photo of my model 1899 Krag carbine, showing the carbine version of the 1901 sight with a rifle-style hand-guard.

Also a picture of a Krag stock with an "H.H." marking and Ordnance Dept. crest.

It is my belief that these markings date from a period of rebuild work just prior to WW1.

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