Tom- in your descrtiption of the patterns, you used poi, stating they balls or slugs were 3" to the right of it, etc.

I think you mean point of aim - poa which is where you are aiming, not point of impact - poi, which is where the projectile actually lands. The slugs and balls/bullet always land on the point of impact - small point and probably nitpicking but misuse of terms can cause confusion. no biggie.