I have an STI Trubor Open gun with a very light trigger pull... It's almost identical to my two STI Edge Limited guns, except that occasionally the hammer doesn't drop when the trigger is pulled... It seems to happen most often after racking the slide to load a round... It doesn't happen often... Last night I shot four stages without it happening, but it did happen once on unload and show clear...
When the issue shows up... I pull the trigger and it feels like the safety is on... If I release and pull the trigger again, the hammer drops... not good... Not sure what could cause that... Maybe not enough pressure on the left leaf of the sear spring?