I'm a bit puzzled by the 'far to the rear' placement of your rear-sight.

Are there other tapped sight holes on the top of your barrel? (They might be filled).

It is possible you have some type of replacement barrel. A real Krag barrel will have a 'P' (proof) stamped on it near the bottom.

How long is your barrel from muzzle to 'closed' bolt face?

What is the Outside Diameter of your barrel, near the muzzle?

Can we see some pictures of the rest of your Stock, barrel-band, and the other side of your rear-sight base?

A replica Krag front-sight base is available from S&S Firearms, Glendale, N.Y. It requires skill and silver soldering to install. This gets expensive fast. You end up with an expensive replica and not a 'correct' carbine.

A better idea of what exactly you have will allow better suggestions.

Some photos to help identify if your barrel is a Krag barrel.

(BTW - When Gunsmiths, professional and amateur, utilized the 'banded' 1903 Springfield sight on 'sportered' Krags, they usually machined a 'step' on the barrel. They reduced the diameter of the barrel, near the muzzle, so that the intact banded-sight base could be driven on and pinned into place).

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