There was a rather lengthy discussion on this in another post. I’ll try to find it and link it below. Whether a PCC, rifle, or even a scoped handgun, if the sights/dot is mounted high above the barrel, it is a good idea to understand the trajectory, even at close distances.
Here’s the OP: AR 9mm Carbine - What Zero to Use?
Here’s a video that explains some of the related concepts:
