Mentioned in other posts, the gun didn't have a shifting poi before it was sent to PA for a de-twang. This (to me) points to a botched tune that seems to has only addressed "spring twang".
Anywhoo.....a most excellent detailed response! I especially relate to "putting all the marks on the scope" comments. Currently I have marks on the AO of my 5-15x50 Hawke Panorama that were put there a couple days ago shooting at my practice lane. Well, last night I was checking out my "near zero mark" upstairs at 18 yards with a lighted target and found that the "near zero mark" on the AO didn't line up with the pointer like it did 2 days ago. I'm blaming most of this on 70 year old eyes that don't seem to focus the same from day to day!