Hey guys I have a KD date code USP 9mm that I converted to LEM. However I decided to go back to DA/SA using updated internals. So I bought the latest sear, hammer, catch, hammer axle, etc. and installed them.
Now SA works fine and DA works as long as I use the decocker, but if I dry fire the gun there is no second strike capability anymore. Now maybe I'm not remembering correctly but I could have sworn that it had second strike capability with the original parts and now I'm second guessing myself.
Anyone know what I might have done wrong here?
Until TooSixy shows up to give a definitive answer, I'd suggest going back in and verifying all of the spring legs are in the right places, and the disconnector and trigger bar are functioning correctly (I'm assuming the trigger bar detent and spring are correctly installed).
The lack of the trigger bar re-engaging for the second strike (which is a capability the USP DA/SA definitely has) suggests a spring or a component is mispositioned such that the end of the trigger bar is not rising back into position to be able to re-engage and draw the hammer back. Maybe the trigger bar is displaced slightly to the left, so it's no longer resting on its detent? TBDS missing?
Shots in the dark, but at least a starting point.
Did you use the right catch ?
I just put my usp back together and I know it would be easy for the plunger to "slip" out and around the back of the trigger bar upon reassembly (when you put hammer and hammer axle in over it) like mneblett said. I don't know if that could cause your symptoms
It seems to be a problem with the trigger bar not engaging whatever its supposed to engage to cock the hammer for a second strike. To me that makes it seem like a trigger bar, disconnector, or control latch problem.
I still don't know what was causing my problem, so I reinstalled the original parts and everything is working fine now.
I tried a few combinations of old and new parts and it seemed each one had a different problem.