I share your frustration. I shoot everything from new Weavers to Zeiss, Meopta, Sightron SIII and Kahles. I have not kept track of anything "official" over the years, but I'm ALWAYS surprised if my adjustments produce the effect they are supposed to. I too tap my scopes after adjusting, just hoping that will bring some magic and the next round will hit the correct spot it is supposed to. Once I get things lined up, maintaining zero is not a concern. They all seem to hold that.
