Move the front base in it's dovetail only if the scope is completely off. The rear "ring" adjustment screws are meant for windage adjustment. Forget about that "bending the scope tube"! The movement is minimal and of no consequence. Unfortunately, the windage adjustment screws are of two arrangements, invisible from the outside. Some pull the top over, others push it . So start loosening one screw just a quarter turn and tighten the other one. Shoot the rifle again to see the movement. Such a quarter turn will move the impact by about 5 inches at 100 meters. A bore sighter is of great help here. As the adjustment screws and/or sliding dovetail are often rusted or gummed up tight, I usually at first remove one screw completely, without touching the other one. Then I apply some penetrating oil (WD40) to the inside. This allows you to see if the mount is of the "push" or "pull" type: if the screw threads are in the lower part of the assembly, they push the scope over, if in the top part, they pull.