Adjustable Objective Scope ?

VaPredHunter

VaPredHunter

New member
How much can the AO affect your shot in a hunting situation were you have to make a quick shot and not have time to adjust the AO? Are we talking fractions of an inch, inches, feet? I am sure its all relative to the distance of the shot. I just wanted to know anyone has ever had a problem? Thank You Chris,

Yesterday I went into a local gun shops to look at some scopes and maybe purchase one. This shop has been in business for over 20 years. I asked the owner about the AO on the scope and how it might affect your shot in a hunting situation were I have to make a quick shot and not have time to adjust it. He said it would not matter the AO just focuses the scope at different distances so you can see better. In an effort not to tell him I thought he was an idiot because he’s owned a gun shop for more then 20 years and doesn’t know that the AO dials out the parallax aiming error. I had no more use for him I just put the scope down and walked out. I have never owned an AO scope just seemed like more stuff to fool with. I try to keep things simple, but this year I saw the need to have a higher power scope on my .204 for groundhog hunting and most of them have the AO. I plan to also use this gun for fox, coyotes and bobcats sometimes the need to make quick a shot happens.
 
Most of my rifles have an ao, mostly because it helps my old eyes when I work up loads and to sight in. Also very handy for the rimfires. What I usually do when hunting is to set it for 100-150 yards or so. Since most non ao scopes are set in that range for centerfire rifles you should be basically doing the same thing, and I don't believe the sight error would be any different. I know some don't like the ao scopes, myself, I'd rather have it and not need it than need it and not have it. Or something like that. Of course, you could end up with it accidentally set really out of wack, just never happened to me yet.
Barry
 
I have one AO scope, a 6 x 25 x56 target scope and it did take me a little while to get use to it. While walking to my calling stand I set it at 50 yards for a quick shot scenario and when I get to the calling sight I'll set it at 100-150 like panhed said. If a shot is further you will usually have time to adjust it, closer it is still in focus.
 
Quote:
While walking to my calling stand I set it at 50 yards for a quick shot scenario and when I get to the calling sight I'll set it at 100-150 like panhed said. If a shot is further you will usually have time to adjust it, closer it is still in focus.


I do just about the same thing as quoted above with my 4.5x14x50mm. Except I usually set mine to 30 yd mark on the dial and power to 10.

I have taken many ole yotes at close ranges (uder 30 yds) with this scope. Back in Feb, I sent a 55gr V Max into the shoulder of an old male - 16 yds. /ubbthreads/images/graemlins/grinning-smiley-003.gif /ubbthreads/images/graemlins/grin.gif
 

I'd listen to your gunshop owner...

Parallax Definition

Adjustable Objectives

From:
http://www.aafta.org/html/education/education_glossary.html

Here is their defs:
Adjustable Objective - The adjusment on a riflescope that allows the parallax to be adjusted so that the target or quarry is in perfect focus. Typically this adjustment is on the front of the riflescope and has distance marking on the adjustment bell.

Parallax - A condition that occurs when the image of the target is not focused precisely on the reticle plane. Parallax is visible as an apparent movement between the reticle and the target when the shooter moves his head or, in extreme cases, an out-of-focus image. Many scopes have a special range focus to adjust for parallax (adjustable objective).
 
If you must have a scope with the potential to adjust get one that has a "left hand focus" knob instead of one that you have to reach around the gun for. From the entry level stuff like Nikko Sterling to the Leupold long range/ tactical stuff, you can find one in your price range that will be easier to use in the field than having to crank on your objective lens.
Also, you can check the AO scope you are about to purchase to see if there is an "infinity" setting on the dial. Some manufacturers have such a setting.
 
I hate AO's-I always find myself leaving it on the wrong setting for the conditions I'm in while hunting on foot.

Hunting off a bench is a different story.
 
Like I was saying I'm more about simple so lack of AO is ok with me just seems the higher power scopes all have the AO. Groundhog hunting this summer I found in my 3-9 x 40 Leupold a groundhog at 400yds looks like a pen dot on a billboard. So what do you do for higher power scope on a hunting rifle? /ubbthreads/images/graemlins/confused1.gif Thanks Chris,

Gun shop owner explained it as if you were focusing binoculars not as if it would change the point of impact if you tilted your head wrong or such. He just didn't understand, I felt he should have been more knowledgeable about it since he sells them everyday.
 
The only reason for having an AO scope is because you plan on shooting at very long, as well as short range. The reason you see them on virtually all high magnification scopes, is because those are the scopes that are normally used for long range.

Most non AO centerfire scopes are set at 150YDs. That will do fine out to 250YDs or so depending on the scope. Past that, parallax will start to affect POI if you don't have a consistent cheek weld behind the scope. If your eye is always in line with the axis of the tube, you will never encounter parallax. The amount of shift will depend on the distance, power, and the position of your eye relative to the axis of the scope tube. At long range, it could become quite significant (5ft or more at 1000YDs).

As others have said, keep it set at 150YDs (by adjustment, not the numbers on the bell), and if you need it for long range you will have plenty of time to make adjustments. Long range snap shot is an oxymoron.

Side adjusting scopes are convenient, but be aware that you should always adjust the parallax down with them. Take the adjustment all the way to infinity, and then come back to where you need it.
 
Your gun shop owner may not be an idiot... he may be tired of making a lengthy explaination over and over to shooters, most of which don't want to know the full story.

The AO or SF is not for focus, it is only for parallax. The AO can be mis-adjusted and the target can "look in focus", (particularly at medium powers), but still have parallax. At high powers, if it is set very off, the focus will look out, but that is a secondary effect.

Below is an interesting read, and was written by a professional in the optics industry, and a consultant to Leupold and Premier Reticles.

It is not something a gunshop owner would want to go into with each customer. Most customers don't want to know the how and why... thay want a quick answer, which is what you got... of course, that withstanding, he might still be an idiot /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/wink.gif

http://www.snipercountry.com/Articles/Parallax.asp
 


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