This Krag has been examined and discussed by those who are much more informed on the subject than myself. It is or it isn't. The NRA Krag carbines were not marked but they have certain features that separate them from the average cut-down rifle. This Krag carbine has three of those features. The bore is shiny and sharp. I've shot it a couple times only and haven't worked with it at all, though I did load and shoot cast bullets only in it. .311" 311299.
1- stock is 1899 carbine stock
2- rear sight is Model 1901 C-marked for carbine and calibrated to 2,300 yards (per Brophy)
3- pinned front sight (per Brophy)
Cut-down rifles do not have those features. So, that's as far as the argument goes.
reference: The Krag Rifle by Brophy