I know this is way old hat but was having issues with accuracy and POI with my 9C. Shot way low and large groups at any but in-your-face distances. Trigger mod did help slightly (4.75 Ibs.), ammunition changes did not. Finally dropped a Storm Lake barrel in and all issues disappeared. Shot to point of aim, groups at 25 and 50 yds. cut in half. Still have 100% reliability as well. In this case, worth it for me.

I have a 40C that was also shooting garbage can size groups sent it back Home and they installed new barrel haven't been to range yet.