Originally Posted by polyphemus
Field strip the pistol and visually inspect all the moving parts for damage here
is when the firing pin travel can be checked for proper function.
What RickB is suggesting is a way to test for whether or not the lever is fully lifting the firing pin safety plunger out of the path of the firing pin. To do that, the slide has to be on the frame and in battery.
One way around the need for a third hand would be to simply drop the mainspring housing down far enough to take spring pressure off the hammer, leaving the slide in place on the pistol.