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What is A/O and what does it really do. I was looking at a Simmons scope (Aetec 2.8-10x44). Mostly hunting and target (not competative). Do I need the A/O? Last question, I've had cheaper scopes where the POI moves when you change the magnafication, do I have to worry about that with these?
 

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the only stupid questions are the ones we don't ask

A/O = Adujtable Objective.

My understanding of the adjustable objective lens is that it keeps the cross hairs in focus at different ranges of distance. I think it also helps with the POI at different distances. Magnifacation on a good scope should have no bearing on POI. To awnser your question on do you need the A/O, depends (in my opinion) on the what rifle it's going on. I wouldn't put one on a 10/22 for target or hunting. But I kinda like it on my 30-06. It definitely helps keep the crosshairs sharp and in focus. I bought a Simmons 4.5-14x40 AO about 2 months ago for my 30-06. I found the A/O to be a little aggravating at first. But I've got used to it. Also I've had no problems with POI moving with this scope.

Hope this helps.
 

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The A/O feature isn't intended to adjust focus so much as to eliminate parallax at a variety of distances. If you aren't sure what parallax is, set up your rifle, or scope, on a solid rest so you won't be moving it at all. Have it aimed at something about 40 yards away and then look through the scope moving your eye from side to side a bit. You'll notice the cross hairs moving left and right in relationship to your 'target'. That little bit of movement will open up your groups noticably whenever you are not shooting at something thats the exact distance your scope is set to be parallax free. All scopes have it in varying degrees because it's a factor of distances between lenses. Better lenses may show a bit less is all. Most scopes made for high power rifles with be built by the manufacturer to be parallax free at 100 to 150 yards. 22 scopes are generally parallax free at 60-75 yards. The A/O allows you to 'dial in' whatever range your shooting at to virtually eliminate it.

Sorry to be so long winded.
 

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Parallax

So if one is to shoot at 50 yards what should the parallax be adjusted to? Now how about 25 yards? Under 25 yards? I ask because I am looking into the Simmons 1022T and want to know what I am getting into.

Is there some formula or helpful guidline that any of you use to determine the parallax setting?
 

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The AO ring has settings on it that correspond to yardage. (30, 50, 100, 200, etc) Usually they're close, but sometimes a bit off. Most people test it at their usual shooting distances like previously mentioned and make their own marks on the adjustment ring if different. If I knew how to post a picture I could show you the adjustment settings. (And I though I knew something about computers)
 

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AO Questions

Blackhawk,

MAKE_____MODEL__POWER__AO LENS__MIN. FOCUS
SIMMONS..1022T.....3-9X.......32mm......7 1/2 Yards

myredchevy,

The AO, as chundoo has said, is to focus the image of the target on the erector lens [where the reticle is] to eliminate parallax.
I've had cheaper scopes where the POI moves when you change the magnafication, do I have to worry about that with these?
Changes in POI due to changes in power on variable scopes is a very common problem with inexpensive [cheap] scopes, as the tolerances used to make these scopes are not tight enough to maintain the optical alignment of the lenses as they move to change the power. On better quality scopes, like the 'Aetec', this should not be a problem. I have a WTC18 [6.5-20X 50mm AO] that does not change POI with either changes in power or AO settings; my AO markings are 'right-on'.....! ! :)
For mostly hunting, you would not need an AO; hoever, for precise shooting at targets or varmints, an AO would be highly recommended.

kingston fisher,

As stated above, the AO is used to focus the image of the target on the erector lens.

To focus the reticle, the ocular lens [eye piece] is used, NOT the AO; this is done once when you set-up your scope, unless your vision changes. Thereafter, the AO is used to focus the target as distance changes; the reticle stays in focus....! ! :)

Hope this helps....! ! :)
 

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So you are supposed to set the AO to the exact distance you plan to be shooting at?????

What happens if you are off by a little?

I ask because I have heard some guys saying that they hunting with the Simmons 1022T and they set the AO for 25 yards or one particular setting and then leave it. I was under the impression that being off by a bit wouldnt matter. I just dont want to invest $100 in a scope if I am going to have problems with it.

By the way I just got a Volquartsen Carbon Fiber Barrel, VQ TG2000, Hogue OM Stock, Bipod, and 3 more factory mags. This is turning into a seriously accurate hunting/paper punching rifle. And you all are to blame. You should be proud!!! :D :D :D
 

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AO Settings

Blackhawk,

Target Shooting:

The AO ring should be set for the exact range at which you are shooting, and then, "fine tuned" by looking through the scope and getting the 'sharpest image' possible of the target; this may be slightly 'off' the marking on the AO ring due to manufacturing tolerances; the higher price the scope, the closer it will be.... ;)

Hunting:

The AO ring should be set for the expected range at which you will see game; for squirrels, set it for 40 to 50 yards; for chucks, set it for 60 to 80 yards; for crows, set it for 80 to 100 yards.

Plinking:

The AO ring should be set for the approximate range at which you will be shooting: set it for 25 yards if the cans are at ~ 25 yards; set it for 50 yards if the clay pigeons are at 50 yards, etc..

Examples:

When chuck hunting with a centerfire, I set the AO for 200 yards; then, if the chuck is between 100 and 300 yards, there isn't any problem....! ! :)

When deer hunting in the hard woods [open], I set the AO for 75 yards.....! ! :)

Hope this helps.....! ! :)
 

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If you're off 'by a little' it wouldn't make a MAJOR difference, but there would be some parallax to deal with. That's no different than having a scope with no AO feature that was set up by the manufacturer to be parallax free at 100 yards and taking a shot at say 150 yards. You have some parallax, but not an enormous amount. It would be a different story if you had the AO set at 25 yards and took a shot at 150 though, or vice versa. Either way you'd have introduced a measurable amount of parallax. If you are real consistent in your eye placement the effects of parallax are minimized, this is where good consistent shooting form comes into play. A nice tight 'spot weld' as taught by the military is intended to keep your eye in the same place all the time. For a big game rifle at normal hunting yardage parallax usually isn't an issue. The smaller targets of a .22 can easily show the difference, expecially if you're using a scope set by the factory at 150 yards and you're shooting at 25 yards, or closer.

whew!
 

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Big Mike and chundoo parallax totally makes sence to me now. I GET IT!!!!!!!!!! Thanks so much for those really great explainations. If web sites told you how to deal with parallax like what I just asked, then I would have understood it a while ago. The examples are what made the difference. Thanks again.
:t :t :t
 

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Setting Up a New Scope

Setting Up a New Scope:

1. Inspect for any damage.
2. Are the AO and Power controls smooth?
3. Does the image appear bright and clear [AO must be set for the distance to the image]?
4. Focus the ocular lens* on the reticle for your eye; not all eyes are equal, and this must be done. If you normally wear corrective lenses while shooting, then wear your glasses for this step. If you wear glasses for reading, but not shooting, then leave your glasses off for this step. When focusing the ocular lens, first look off into the distance for about a minute [so your eye accommodates to distance], and then quickly look through the scope at a blank surface [wall or sky]; is the reticle clear and crisp? If not, adjust the ocular lens 'out' 1/2 a turn, and then repeat; if it is better, then give it another 1/2 turn 'out'; if not, give it a full turn 'inwards'; repeat until you have a clear and crisp image of the reticle [ignore what the target looks like]. Remember, each time look off into the distance for about a minute before looking through the scope......
5. Adjusting the AO for target shooting: This should be done when you are at the range [or the place where you shoot]; initially, set the Power to its highest level, and turn the AO ring to the 'marked' range at which you are shooting; if your target is at 50 yards, then turn the AO ring to "50 Yards"; now look at your target through the scope: is it clear and crisp? If not, turn the AO ring ever-so-slightly to the left or right until your target is clear and crisp. Now, set the Power to the desired level. DONE, until you change your shooting distance.
6. Adjusting the AO for hunting: This should be done just before you enter the area to be hunted; set the AO ring for the range at which you 'expect' see game: squirrels - 50 yards; woodchucks - 100 yards, etc..
7. For Non-AO scopes [rimfire and air gun], steps #5 and #6 are omitted. They are pre-focused for ~ 50 yards.
8. Sighting-in the scope is a separate issue.

* Ocular Lens = The eye piece of the scope [at the back end]: The ocular is used to focus the 'image of the reticle' for your eye.

Good Luck...... ! ! :)

[Copied from a Post I made 28 February, 2002]
 
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