CORRECT!marine6680 said:Sight picture will vary based on distance to the target and the load you are using.
A pistol that hits well with a 6 o-clock hold at 25yds, may need a standard hold at 7yds. (sight pic 2 above)
A pistol may use all three styles for different ranges.
Because the bullet trajectory does not align with the sight line, the point of impact on the target will vary from the point of aim depending on the range to the target.
Here's a test I did with one of my pistols awhile back.
https://thefiringline.com/forums/showthread.php?t=503476
One look at that plot will make it clear that there's NO WAY for a pistol to shoot to exactly the same point of impact at different distances with the same point of aim.
It is possible to get a flatter trajectory than is shown in the picture, but there must be some variation in the point of impact due to trajectory differences as the range changes.