Tm 5.1 has been stumping me for weeks.
 

On my TM 5.1 the nub on the right side of the lower frame lowers properly and the hammer works fine. But when I install the slide, when the nub is depressed as the slide 'slides' over it, it fails to raise as far as originally, and thus the trigger will not release the hammer.

I've spent well over 50 hours scrutinizing my gun over the past 3 weeks with no success.

Anyone experienced this issue? I'm dieing to get some help.
Thanks