I have a Colt lighting medium frame rifle which I am trying my best to get back into working order. When I got it was missing parts, and I was able to obtain or make the parts I needed. It still has a few minor problems but the major problem is the action (pumping the slide) is very stiff. It seems to function properly but is very hard to pump. Have any of you out there run into this problem? Any and all help would be appreciated. The gun dates to 1891.