Newbie needs help on AO

[RMC51]

I have a Weaver scope K9-B. This thing has AO. What is AO? how does it work? how do I use it? The front dial has 50ft, 75ft, 100ft 50yd, 100yd, 200yd, 1000yd settings. What do these AO settings do? Is there a manual /book I can read about this AO thing.

Scope is 3x-9xAO mounted on a Winchester M70 pre 64 30-06. Is this a good match up?

[wogpotter]

"AO" means Adjustable Objective, it basically works like focusing a camera.
Do you need to focus your scope? Maybe, it depends.

Let me explain a little.....


Close shots (under 100yds) probably need the objective focusing, but if you're hunting how much time do you have at under 100yds? So, based on that if you either hunt beyond say 75 yds, don't target shoot under say 50 yds, & don't mind backing the magnification off a bit (focus gets less critical as you reduce magnification) you don't need an AO scope.

However....... if you want to target shoot with real accuracy (sub MOA talk here) the AO reduces/removes something called parallax. This is a good thing as long as you take the time to mess with the adjustment. Unfortunately the marks are at best, approximate. To really get best bang for the buck from an AO scope you need to trim (adjust) your particular scope. Does it work? yes. Do you have a use for it? I don't know, maybe you do. Can you just dial in a marked range & get some improvement, yup. Is more possible with a bit more work, again, yup!

[g.willikers]

With an adjustable objective scope, you only focus the eyepiece to make the crosshair clear for your vision.
The focusing for the target is done at the other end, with the AO.