Made some progress, though a long way to go to improve constantly. One of the crucial things seems to not bend your upper body sideways and try to keep a stable, upright triangle between shoulders and gun, turn as a whole the upper body. Also knee and feet position are of importance, IMHO. So on wide arcs (> 45 degrees) I have to move my feet, too, so I don't have to turn my shoulders outside my stance. True? I also recognised that my sight picture is now focussed on the target, not on the front sight anymore.