How common is POI shift with AO adjustment?

[Methuselah]

Here is a picture of rifle scope optics. The point of the cone where it says "first image plane" is what I meant in my previous post. If the front lens is not perfectly square to the axis, or the objective wobbles on the bell, it will appear to move the reticle. The reticle IS NOT moving, the IMAGE is moving. Same effect, though, POI changes with AO adjustment. I hope this helps.

Where my understanding completely breaks down is focusing 2" away seems to make paralax correction impossible.  I mean without trying to speak to the technicals, if you mounted a camera, that takes eye position movement out of it, it should still move but maybe "nudging" the AO will put it back.  IOW, at 2", what if the movement is just eye position movement?  That's why I said not to use the gizmo this way.

[sscoyote]

Steve do you have a grid boresighter? I have already proven that it, in fact, does work this way, more than once, and others have too. It's very simple to prove this theory. I shot just today with this optic I'm having trouble with and the groups moved exactly as the gizmo showed me it would-- 7' down and slight horizontal movement with extreme parallax change at 50 yds. (~3.5") with my 22 LR.

This optic "clicks" too at the extreme ends of the parallax change and without the BSG I can't see the reticle image change but it's blatantly obvious with the BSG.

Many of my other optics have only very slight to no change at all as viewed through the BSG, but thanks to this tool it can be seen as soon as I mount the optic.

I'm not saying that it shouldn't be tested at the range, but every time I've seen this sort of problem, it's been proven on paper.

[Methuselah]

7' down and slight horizontal movement with extreme parallax change at 50 yds. (~3.5") with my 22 LR.

What does extreme paralax change mean? Are you introducing an error how.  Im not understanding, parlax error that won't adjust out is a broken scope, right?  I guess a broken scope can show up on a BSG.  I think using the BSG in an invalid way could also lead one to think the scope had an issue though, right?

This optic "clicks" too at the extreme ends of the parallax change and without the BSG I can't see the reticle image change but it's blatantly obvious with the BSG.

Extreme ends, you mean closest focus and infinity?  If its an AO hitting end of travel, is that how you end up using it?  Most of my shooting is between 10 and 43 yards, or are you speaking of adjustment of a fixed parallax scope?

Guess I'm just lost, sorry, but thought main use for that gizmo thingy was getting 1st shots on paper.  I really think it would be neat if it had other uses, but communicating this way seems to make what you describe hard to follow.

Can you point out a youtube vid showing what you are trying to do?  I really would like to be wrong on this account!

[sscoyote]

Steve, the fact that almost all my other scopes and some friends (maybe 15 or so scopes) have either no reticle image movement or just slightly perceptible movement USING THE EXACT SAME METHODOLOGY points very strongly to a defective SF parallax adjustment with the optic i detailed above, as well as another use for an optic's tool. As i am watching the reticle image on the grid, the reticles axis moves about 7' or so along the grid, and at several points the entire reticle image jumps left and right as it's being adjusted especially at the ends. It's usually very easy to see if something is not being supported correctly in most moving systems--parallax adjustment being one of them. Then shooting verifies the problem. I know about head bobbing. I've been bobbing heads for years testing parallax adjustment. I know how to test this. This optic's parallax adjustment IS defective, and the BSG helped in the diagnosis of it--at least this is what i believe to be the conclusion of a logical testing system.

Also to borrow a quote myself i heard awhile back, "I don't care what a tool is designed to do, I want to know what it can do". I give you the grid boresighters.

Reticle image movement is a common problem with parallax adjustable and variable power optics as i'm sure you know. Considering how precise these systems must be it's truly a miracle of science to think that most work as well as they do even after multiple use behind heavy recoiling guns.

[Methuselah]

Considering how precise these systems must be it's truly a miracle of science to think that most work as well as they do even after multiple use behind heavy recoiling guns.

Well, I don't want to steal Andy's thread but I don't agree from the two examples of BSG described behavior it proved Andy's scope was defective.  Yours, yes I agree but like you said - you knew without the gizmo.

I expect an AO to move against thread adjustments in a circular pattern (but come back relatively close) when inspected by what amounts to an optical microscope.  Just don't see it helping Andy   

[sscoyote]

Hope you get the chance to research one yourself someday Steve. Sure has helped me over the years.

[vigilandy]

I'll tell you what guys,  if I can't get Nikko Stirling to replace or fix this scope,  I will be happy to send it to anyone who wants a closer look.  This may be one of those things that make more sense when you have the scope in front of you!

[Methuselah]

I'll tell you what guys,  if I can't get Nikko Stirling to replace or fix this scope,  I will be happy to send it to anyone who wants a closer look.  This may be one of those things that make more sense when you have the scope in front of you!

I would love to help out, but the only one that's half way accurate is a pumper with max usable range of about 30 yards 5 times a year when the wind is calm.  The Hatsan 125 would hammer it to death (weaver mount too)

That said, I'll try if nobody else will and if it's good I'll return it.  I hope someone with an accurate shooter steps up, especially after all you've gone through!

[sscoyote]

I'd also love to Andy, but between night shift (and night shift recovery--30 yrs. of it now), grandkids and family-dos, i hardly have time for anything else these days. Good luck with it though sir. I hope you get it ironed out or money back.