It all depends what you shoot. When I change from Win. Hi-Vel. to H-13 #6's, my POI is about 8"-10"'s low. The more potent the load, the higher it will shoot. If you shoot standard velocity shells with the same payload (or close), they probably will pattern closer to each other.
This is the same for rifle shells The heavier the bullet, the higher thay will shoot, when compared to the same shells with a lighter payload. It goes beyond what you would think, but it is fact..Hope this helps..Mike