What OKF said (as usual).
Besides, the only way there would be to adjust POI up and down (elevation) on a gun with fixed sights, would be to mill them down, or replace them with shorter one's. I'd tend towards wanting to try using sand bags off of the bench with 3 shooters at a specific distance, all firing the same ammo, at the same size target. Only if all 3 shooters group in the same spot on their target's, would I condemn the weapons sights. YMMV?