I'm going to jump in here since we're on this subject. I just bought a used USP in .357. At 7 yds. it was hitting 6" low. I noticed that there are trijicon sights not factory sights. I decided to replace the front sight with a factory sight but there are options in thickness. How do I determine which sight would have been originally installed?
If there were options you would have to ask the original buyer what they picked. Hope you know the POI POA is behind the front dot not above it on the USP.