Cant go too in-depth since I don't have the knowledge to do so, maybe a gunz developer can explain it better, but basically when the shotgun barrel is at the start of the switching animation and there's obstacles in the way, the spread generates where the barrel is and not where the crosshair is, I think this is due to the code that takes care of edges and walls, for example:
https://i.imgur.com/sVcOviF.jpg
In this photo there are multiple edges and corners, if the code was just to generate a flat spread and not compensate for edges, it would not hit the walls in this manner and just go everywhere else but the middle.
So in the Port clip, the barrel is facing the left side which also has an edge, the game executes the code that takes care of edges and such.
Same thing applies to potshotting while climbing, have to wait till the barrel is straight and then fire, otherwise it wont hit.
TL;DR
https://www.youtube.com/watch?v=kdkn..._channel=Amers
Cant go too in-depth since I don't have the knowledge to do so, maybe a gunz developer can explain it better, but basically when the shotgun barrel is at the start of the switching animation and there's obstacles in the way, the spread generates where the barrel is and not where the crosshair is, I think this is due to the code that takes care of edges and walls, for example: