Problem with CZ75B SA hammer not dropping when trigger is pulled

[Bret]

I took my CZ75B SA to the range today along with the new CZ threaded barrel that I fitted to it yesterday.  I shot 25rds of Winchester NATO 124gr FMJ through it without issue.  The pistol actually seemed to be more accurate with the new threaded barrel than the original barrel.  That's the good news.  I then started shooting some Federal American Eagle 124gr FMJ NT.  After successfully firing a few rounds, the hammer wouldn't drop when I pulled the trigger.  Sometimes I could pull the slide back a bit, let it forward and then it would fire.  Eventually, it wouldn't even fire.  I unloaded the pistol fiddled around with it some.  If I pull the trigger and pull the hammer back with my thumb, the hammer will drop when I release it.  As you might expect, I was thinking this had something to do with the new barrel, so I reinstalled the original barrel.  It didn't make any difference at all.  The hammer just won't drop when I pull the trigger.  Any ideas?

[Boris_LA]

Check the over-travel screw in the trigger. It might walked out and preventing rear trigger movement too much. Locktite it in place.

[Bret]

Boris_LA, you nailed it.  It just took a 1/4 turn, once I figured out the right direction, to get it working again.  The Locktite is drying now.  I'm very relieved.  I thought that perhaps I had screwed something up when I fitted the barrel.  Thanks for your help.

[The Guardian]

All is well, ahh...happy endings, sounds like its time for a group hug......

[Boris_LA]

Glad it was not something more serious.