Tightening M1901 sight windage binding lever

[Rick_the_Librarian]

I had to take apart my new Krag for cleaning purposes (it was dirty and had some surface rust). I took the rear sight, a M1901, apart and although I've tried several times, I can't get the windage binding lever to be tight after assembly. I've started with it in the left position when I assemble it and the screw is tight - it partially tightens - but only in the far right position.

Any pointers??