Since you have to remove your scope to check the ring mounting screws, stand the scope on a hand mirror on the lowest magnification and look into the scope. You will see two reticles. Adjust the scope reticle until you see one imposed over the other. Hold the rear of the scope in one hand and whack it into the open palm of your other hand and check the reticle alignment with the mirror. Check it more than once if the reticle didn't move. If the reticle did move, recenter the reticle and see if it moves again. If the reticle moved your scope is bad.
