Most semi auto shooters don’t shoot well enough to know their different loads made have varying POI.
Let’s consider variables that could effect POA/POI. In no particular order.
1. Sight dimensions.
2. Sight design (Heinie offset right).
3. Sight installation. (Glock shipping many G5 pistols with the rear sight a smidge right).
4. How that particular pistol is built.
5. The position of the sun. Light condition generally.
6. Shooter’s eyes.
7) Shooter’s technique.
8) Different load and even different lot of ammo.
9) Distance shot at.
10) Shooting position — freestyle versus rested.
11) Trigger components and characteristics.
12) Backstrap, GFA etc, installed
13) Speed of shots fired.