What have you tried? Make sure that the rings are clear of the radius's near the objective and ocular pieces. An 1/8 away is a good minimum distance. Not knowing your experience level....You did not mention the maker and style of rings, Try some rings that are of higher quality. You said you had a vortex, you mentioned magnification, you did not mention the model. Much more important. If it is a cheaper model try a better scope. I would not change rings or bases unless I found it to be the problem. Rotate them move them front to rear and vice versa. Prove the issue. Turn the base backwards if it is a zero mount. Prove it!