the point of impact should not have changed that much. ive used variable scopes for a long time and never noticed my rifles point of impact moving that much. maybe an inch or less. id take it to the range and check the zero on it. try shooting it both with a low power and a higher power setting on the scope and see if it changes. also turning the scope up to say 9x or higher causes aiming to be more sensitive as its easier to move off center then when at a lower setting. with the deer that close you should not have needed the scope turned up that high. i very seldom turn my scopes up that high when hunting. usually never go over 4 or 5 power.