Did you try switching the 'lever' on the left-side of the action 'up'? This is the "Magazine Cut-Off" lever.

It is used to block the magazine feed of cartridges so that the Krag works as a 'single-shot', holding the cartridges in the magazine in reserve.

Unless you still have an early style of "Cut-Off",  the lever should be 'up' to feed and 'down' to block. (Early cutoff-levers functioned in reverse).

In your photo the cut-off lever is in the 'down' position, which suggests things are working correctly and the cartridge feed-path is 'blocked' by the cut-off's shaft.

---