this is why I don't buy PA scopes any more.. unless you are spending say £200+, it's pretty well guaranteed that PA adjustment will result in POI movement. Luckily for 12 FP airguns, 95% of shots are in the 20-40 yard range, so just PX your non AO scope for 30 yards and job done. Less stuff to go wrong, less weight, and more money spent on the lenses If I do happen to acquire a secondhand PA scope, 99.9% of the time I'll set it to 30 yards (real, not what is written on the bezel) and never move it. If you are doing 40 or 50 yard benchrest, fine, adjust the PA, and rezero. But most of us don't
Keeping to sensible sized objectives max 40mm or maybe 44 helps reduce PX error too.
Zoom is somewhat usefull than AO, in as much as I leave my 3-9x on 9x all the time, but if I need to shoot something at say 10 yards, you can always wind the zoom down to 3x, enabling you to see it clearly enough, and any PX or POI movement at 10 yards is pretty much irrelevant
Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.