At five pounds, your trigger pull is right in the middle of the factory’s permitted range, which requires that the trigger hold a four pound weight, but drop the hammer with a six pound weight.
Your pistol’s trigger over-travel adjustment screw is an often under-appreciated feature. It is left unadjusted when it is installed at the factory, because it would consume too much of an assembler’s valuable time to adjust it properly. So, it should be one of the first things to get your attention. From your photos, it does not appear to have been adjusted for minimum over-travel, yet. What I do is turn it in until the sear won’t release the hammer, then back it out until it just barely does. With the trigger kept fully pulled, I slowly lower and raise the hammer repeatedly, while carefully checking by feel to be sure the sear does not even lighten bump the half-cock and full-cock notches. I then back the screw out another quarter turn and call it good. When adjusted in this way, the five pound trigger pull can be made to feel mighty nice.
Ex, any chance of the screw working its way back in via vibration to the point that the trigger won't trip the sear?
