Leupold AO (Parallax Test)

G

goody523

New member
I tried an interesting field test yesterday and am wondering if anyone has experience that either confirms or contradicts what I found. I am in the market to buy a new Leupold scope for my .204 Browning Varmint Stalker and after shooting my dad's .22/250 out in South Dakota with the new varmint reticle I am sold on that set-up (less clicking = more shooting). I have always hated screwing around with the AO on the front of scopes as it is not convenient to reach so I was considering a side focus (LR) model.

I went to the range an set up my dad's 4.5x14 with AO and another 4.5x14 without AO (both Leupold's) on bench vices where the gun was completely unable to move and cranked the magnification up to 14X to exaggerate the results. I set the AO on the scope that had it to 100 yards and centered the crosshairs on the target then took my cheek off the stock (so I wouldn't move anything) and moved it around as much as I could while still keeping a sight picture and the crosshairs didn't move off of center - just like you'd expect. I then adjusted the AO to 300 yards and as expected the image got blurry and the crosshairs moved around quite a bit as I moved my head. I threw the gun with the non-AO scope and it performed as expected at 100 yards - clear image and no parallax issues. So far, everything is as expected.

I then repeated the test at 300 yards and this is where I was surprised. The crosshairs on the scope with the AO adjusted to 300 yards did move around slightly when I moved my head. I tried adjusting the AO to the point where it said 300 yards and where it was the clearest focus (according to the bell that was just over 400) and had the same results. Certainly not too bad, but definitely some movement (again the gun is in a vice and my head is not touching the stock so the gun itself is not moving). I then tried the same thing with the non-AO scope and the crosshair movement there was not any worse than the scope with the AO! This really surprised me as I expected to see the crosshairs move considerably at that distance on a scope that is set to be parallax free at 100 yards.

Based on my little test it seems that the non-AO scope performed just as well as the AO scope and not only is it cheaper, it is one less thing to deal with when using the scope in a hunting situation where you don't have time to mess around with a focus knob. I bought my .204 mainly to shoot small things at long distances so an AO scope seemed like it made the most sense, but now I am beginning to think I may just buy the straight 4.5x14 40mm VX-III without the AO. This sort of confirms my experience in South Dakota where I was hitting prairie dogs out to 550 yards with my Leupold Vari-X III 3.5x10 Tactical (with no AO) pretty regularly and the other old timers out there thought I was out of my mind trying to use a scope like that at that distance (they all had 20X and up scopes with AO). I thought that maybe I just happened to have good check weld on my Remington VLSF (Remington 700's have always fit me very well), but my little test at the range makes me think the whole AO thing may be a little overblown. Either that or I am a dunce and am just missing something - can someone enlighten me as to the flaw in my little experiment?
 
Parallax is going to show up more at higher powers and longer distances. Your non-AO scope is (probably) set for a little more than 100YDs and with only 14X you won't see much parallax at 300YDs.

With a good scope you should be able to adjust ALL the parallax out of it at any range. Try moving your head from side to side AND up and down. if there is a difference in the apparent amount of movement of the reticle (parallax) then there is a problem internal to the scope and you won't be able to "adjust it out".

If you decide to get a side AO scope remember to take the adjustment all the way to infinity and then adjust down. Otherwise you will cause problems.

No flaw in your reasoning. Much of the lure with AO scopes for most people in most shooting situations is hype. Unless you are shooting high power scopes at long range, an AO is pretty much a gimmick.

By the way, if you can always keep your eye centered on the axis of the scope, there will never be any parallax at any distance.
 
I read the post about 4x, but it still does not make any sense to me. If I read you correctly, in your experiment why don't you want to set the parallex correspond to the correct yardage, having the parallex set on 300 for 100 yard target.... what's the idea behind that?

BTW, I never go by the yardage index on the scope, it's mostly for reference only, I aways adjust till the crosshair stop flowing in the sight then I fine tune the eye piece till the sight picture is crisp/sharp.
I also find that it does not have much affect when PD shooting, the crosshair does not flow enough to come off target but the mirage is what I have trouble with.
 
I only set the AO at 300 when the target was at 100 just to see the effect, which was very noticeable. What was odd was that the scope that did not have an AO was not any different at 300 yards than the one with AO that was set to 300. Effectively my conclusion was that at the range and magnification I was testing the AO scope did not help at all if it was set right and hurt you if it was set wrong - basically there was no upside to the AO at all (and it's more expensive to boot).

Possibly the answer is in the first reply in that it becomes a bigger factor at longer distances and higher magnifications - neither of which are an issue for me. Also, like the first poster said, if you don't move your head around on the stock it isn't an issue at all.

Unless someone blows a gaping hole in what I believe I observed I am going with the non-AO model.
 
Couple years ago i was trying to get a big XP-100 handgun to shoot @ 100 yds., using a Burris 3-12X LER scope. The parallax was set to 200 yds., and for the life of me, it wouldn't do any better than 2". Finally checked the parallax, and sure enuf it was the size of the group. When i adjusted it out the gun shot a .75 MOA gp. That was a lesson hard learned.
 
I am guessing that parallax adjustment on a pistol scope would be a lot more useful as there is a heck of a lot more chance for variable eye alignment than there is with a rifle where you have fairly consistent head placement on the stock. I think in my case since I am:

1) Shooting a rifle
2) Shooting over a fairly narrrow range of distances (of which the fixed parallax is set roughly in the middle)
3) Not using excessive magnification

The non-AO scope is the way to go (price and simplicity). I am guessing that there are a fair number of other guys who fit my category as well.
 


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