Mogley,
Take the scope off and throw it away! Start over with either a scope you know is good, or buy a new one. Bushnell Trophy's are reliable and don't move with a power change. From there go up to Burris, Nikon, Weaver, Leupold, as the budget allows. Even two older Tasco's (Japan Mfg.) 10-40X 50's didn't shift zero with power changes. I fired Groups set at 10, 15, 20, 25, 30, 35, and 40X one shot at each setting(7 shot group) that measured .623" in the 22-250, and .594 in the .243. Based on this with low end scopes($$) yours is usless as a variable. You could sight it at one power and never change it, or replace it.