There's a lot of paralax in the AK setup. The sights are atop the gas tube, which is atop the barrel.
You cannot sight an AK in at 25 yards for this reason. It's not the ballistics that make this impossible, but rather the paralax of the system.
Move out to 100 yards for any serious sight setting activities.
That I could be wrong is an eventuality that has not escaped me. I just painted the pictures as I saw them. I do not know how to do anything else. (Saint Elmer, 1955)