In my guns the poi shift is consistent if your using the same gun, ammo and brake / suppressor
change any of that and it's going to have a new POI. For example if I shoot with a
muzzle brake and add a suppressor to the muzzle brake it will change the POI
Let's say you have two guns running the same muzzle brake and you move the suppressor
from one gun to the other - on one rifle it changes it 2" and the other 4". But it is repeatable.