I am in the process of replacing my trigger and hammer group.. After installing I tested all parts (not firing) to insure correctly working. I'll try to explain the issue:
This is all done with the upper removed and checking for function.
1 - Cocked hammer and checked that Safety worked - OK
2 - Placed safety to fire, pulled trigger, hammer fell - OK
3 - While holding trigger rearward re-cocked hammer to test disconnect - OK
4 - PROBLEM - This only happens occasionally but once is not good. On occasion while holding the trigger and re-cocking the hammer the disconnect engages the hammer, but when I release the trigger the hammer disengages from the disconnect but by-passes the trigger sear and falls all the way.
I tried many combinations of my old trigger, hammer, disconnect with the new parts to isolate the issue. It come down to the hammer's engagement with the trigger sear.
Could it be a faulty machined hammer?
Any suggestions. I'm ready to just purchase a new hammer but curious if anyone has had the same experience.