Hi there! First time poster with a technical question. If a scope does not hold zero (lost 5" of elevation without any known cause - no drops - non-magnum rifle), and then comes up 6" when it is only adjusted to come up 5", then can I basically write off all results from this scope? I feel like I can not differentiate shooter error from the potentially random effects of my optics. I can say that I shoot much better with what should be an inferior rifle, and have been struggling to tighten up groups on this new gun. Thanks!