Stiff to open and almost snaps itself shut when you start to close it. Besides the spring, I think there's a cam surface involved but its been years since I looked at the parts.
While it lost out as a "not as easy, simple or practical" as the Mauser and other stripper clip systems, one has to give the Krag system points for ingenuity, and a degree of elegance in the design.
Open the box, dump in loose rounds, close box, and as long as the bullet it to the front, it feeds. No rimlock, no stripper clip, and it allows the magazine to be topped off, without opening the action.
If you want real class in an old school and old world kind of way, find a Krag in 6.5x55mm.