Dave:  I may have made inserting the Krag magazine-door hinge pin sound too easy.  It does involve a fair degree of grip strength.  I pulled one of my Krags apart today just for practice.  It is important that the hinge pin is straight.  Also test that every thing lines up by partially assembling with out the flat spring.  Make sure the tip of the hinge pin is not "mushroomed" and inserts easily.  On my Krag, I can hold everything in approximate alignment and start the hinge pin in.  I then with one hand squeeze the magazine-door against the spring in a bouncing action.  With the other hand I apply pressure on the hinge pin.  It slides in and the tappered tip begins to enter the hole at the rear of the magazine well.  Slight taps with a screwdriver handle seat it fully.  I then rotate the hinge pin into the locked position.  Excessive pounding on the hinge pin will cause it to bend and should not be necessary.  With practice, one develops "Krag muscles".