AO scope or not?

jes

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If you are using a scope of less than 10x, do you really think an AO makes that much of a difference? I mean if the scope is set for 100 yards, how much difference will it make at 50, I have heard that unless you get up into the higher magnification, it really doesn't matter. Any opinions would be appereciated.
 
As long as you keep your eye centered properly behind the scope, the AO doesn't do anything for you. In the really high powered scopes it helps get a perfectly clear picture, especially if you try to shoot at close range with an air rifle or .22. At 10 power I think that it would be a complete waste of money. Move your head around behind the scope while observing the position of the crosshairs on the target and you will get a pretty good idea of how much parallax error is possible at the distance that you shoot.

Then stop moving your head, and start shooting!

John
 
On my Bushnell 6-24x unless I adjust the AO for the range, I don't get a clear picture when on 24x.

I haven't noticed much difference on 6x

I personally always spring for the AO scopes. I like them.

Your mileage may vary.
 
jjohnwm said:
As long as you keep your eye centered properly behind the scope, the AO doesn't do anything for you.

Wow.....that's a bold statement. Parallax error occurs at all ranges and magnifications, just to lessor or greater degrees. Accuracy can be improved by eliminating the variable of parallax error at any range.

Now, some people choose to "hold over/under" rather than adjusting their zero for the range they are shooting. Perfectly fine if you choose to do that, and if that's your style, you probably wont benefit from parallax adjustment either.

But if you're the kind that likes to wring the absolute maximum out of your gear, then an AO scope is a must. One more variable gone from the equation.

In the really high powered scopes it helps get a perfectly clear picture, especially if you try to shoot at close range with an air rifle or .22. At 10 power I think that it would be a complete waste of money.

I guess that depends on your definition of waste and accuracy. I only shoot 7-50m, and I use AO scopes with target turrets.

Move your head around behind the scope while observing the position of the crosshairs on the target and you will get a pretty good idea of how much parallax error is possible at the distance that you shoot.

That will demonstrate the parallax error effect, but it wont help anyone accurately gage what the error is, or eliminate it in a repeatable fashion.

BTW, there are some "sleeper" scopes out there, that have AO at an extremely good price point. The Bushnell Sportsman 3-9x32AO and the Simmons .22Mag 3-9x32AO both offer repeatability, clear optics and AO in the under $100 class. You don't need to by a 6-24x50 sidefocus AO to get a reliable AO scope.
 
skeetgunner said:
Wow.....that's a bold statement. Parallax error occurs at all ranges and magnifications, just to lessor or greater degrees.


Someone please correct me if I'm wrong, but parallax is caused by the focusing of the image and the reticle in two slightly different planes, which causes the crosshair to wander about the image if the eye is not perfectly centered behind the eyepiece. An AO allows the image to be focused in the same plane as the reticle, regardless of the range. You just use the AO to move the focus of the image to the same plane as that of the reticle. If you keep your eye centered behind the eyepiece, a discrepancy between the two focal planes will exist at any distance other than the one for which the objective is focused, but by keeping the eye centered this discrepancy will not result in a visible parallax error.
 
"Parallax is the apparent movement of the target relative to the reticle when you move your eye away from the centre point of the eyepiece. It occurs when the target does not fall on the same optical plane as the reticle. Maximum parallax occurs when your eye is at the very edge of the exit pupil."

According to Leupold, their 4x hunting scopes, focused for 150 yards, have a maximum parallax error of only 8/10" at 500 yards.
 
According to Leupold, their 4x hunting scopes, focused for 150 yards, have a maximum parallax error of only 8/10" at 500 yards.

That may be, but if you plunk that scope on a .22 and use it at 25 yards I would guess the maximum parallax error would be well over an inch. The effect is more pronounced at short ranges than long and even more so for higher powered scopes. I have seen parallax error of over 3" at 25. Thats about 12moa of potential error.

My hats off to all you guys who can keep your eye perfectly centered behind the reticle without fail, shot after shot. I have put a lot of rounds downrange but I never mastered that trick. I would never think of entering a competition with a scope that leaves parallax error as a factor to contend with. Hunt yes, plink, sure, but when short range accuracy counts I have to have AO or at least a rimfire specific scope that is parallax free at the distance I am shooting.
 
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Just a response to the generality of the original post ... and not the
specifics of short range use or competition.

And a 2-7 Leupold VX II (without AO) IS VERY accurate at 25 and 50 yards on a .22 ... well under MOA !!!
 
I wasn't trying to slam your scope, berettaboy.

I am sure the scope you have will shoot under MOA at 25, , but IMO the potential for greater error exists. Set it at 7x, put it on a rest with the hairs centered on a small target grid at 25, and move your eye from side to side.
I am guessing you will see more than 1/8" of apparent movement to either side of center, which translates into 1MOA potential error.

My point was just that maximum parallax error in inches at 500 yards is often less than at 25yards. The specs from Leupold for 25 would have been more relavent. Saying that there is only .8" max error at 500 does not translate into .04" at 25, for a scope set to be parallax free at 150 the potential error is generally much greater at very close ranges than at very distant ones.

I am not saying non-AO scopes are no good. Low powered non-AO scopes are absolutely fine for their intended purpose. However, rimfire-specific scopes set to be parallax free at 50 yards have less potential for error at typical rimfire ranges than centerfire scopes set to be parallax-free at 100 or 150. The higher the power of the scope, the greater the potential error. If you use a 4x scope for hunting, you do not need AO. A typical 3-9 power deer scope on 9x at 25 yards will have significant potential for error, and I personally get noticeably better results with an AO scope. Shooters who hold a perfect cheek weld every shot for may not. If you use 36x scopes for benchrest shooting at short ranges like I do, AO is indispensable. I have not met a competitive rimfire benchrest shooter so good he or she does not need AO.
 
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