Your Krag, #482680, was manufactured around August, 1903, as a model 1898 rifle. The barrel is likely a cut-down rifle barrel.

The front sight is a commercial one, like W. Stokes Kirk utilized.

The rear-sight is a mixture of rifle sight parts: 1898-sight base and 1902 or early 1903-sight top. It is probable it was assembled from surplus parts.

The whole rig looks like the improvised 'carbines' sold by the W. Stokes Kirk company to sportsmen in the 1920s and 1930s.