Just been trawling through the internet on the nightforce website looking at manuals. It says that if the reticle focus is at either end of its limits, then parallax error may be present. I've said before that the eye relief is picky. Shooting without specs, which I usually do, needs the ret to be at its bottom limit. I must say that I've checked for parallax at this setting and it seems ok. Certainly nothing major. However, could be a route worth exploring and resetting to use wearing specs. I hate wearing specs when shooting and don't feel comfy, but if it solves it, it looks like being uncomfortable.