I have not got acceptable accuracy with 180 grain factory loads with my Glock Model 23.
I tried 165 grain factory loads and accuracy improved big time.
Sometimes it is just the gun. I will say this, my agency has issued Glock 23s since the 90s and we use only 165 grain ammo. We have sent several new hires through the academy who have come back awards and many of us have 100% scores on qualification days.
Im a Glock fan .. I really like the 40 S&W ... So I own two Glock 23 pistols
Both Gen 3 .... And a Glock 27 is my EDC ... I only run 180gr in all of'em