Adjustable Objective, FOR WHAT?
Question:
OK, I have been looking to get a new scope, and I keep seeing some with Adjustable Objectives. I looked at my buddys 3X9X40 AO and asked, "what does this adjustment ring do?" And he just said, "oh, I dunno, I never have touched that." It was pretty clear he didn’t really had to torque it to get it to move. So, what does it do? Why is it better? I would think that it would suck to have to adjust the RANGE and the POWER, because I hear soo many guys complain now about haveing to adjust the power and loosing a close shot because they had the scope cranked all the way up. Why would anyone want to have to mess with two settings? I would have to think that if you have the same exact scope, say a 4-12X50’s sitting side by side, one with AO the other without, i would have to believe that the AO better have a BIG advantage to make me want to have to deal with the extra adjustment. So what is AO? Why? When? How? … Rob
Response:
Robert, The Adjustable Objective AO ring on scopes are usually found on relatively high power scopes. The AO serves to adjust the parallex, or double imaging, that occures on high power scopes at long range. To me a scope with the AO ring set to long ranges or infinity, seems out of focus at closer ranges and vice-versa. Usually I set it for the range I expect to see game at and don’t worry about it unless I have to. This definition may be wrong, but it’s what I have noticed. Mike in Oregon – Hide quoted text — Show quoted text ->OK, I have been looking to get a new scope, and I keep seeing some with >Adjustable Objectives. I looked at my buddys 3X9X40 AO and asked, "what >does this adjustment ring do?" And he just said, "oh, I dunno, I never >have touched that." It was pretty clear he didn’t really had to torque >it to get it to move. >So, what does it do? Why is it better? I would think that it would suck >to have to adjust the RANGE and the POWER, because I hear soo many guys >complain now about haveing to adjust the power and loosing a close shot >because they had the scope cranked all the way up. Why would anyone want >to have to mess with two settings? I would have to think that if you >have the same exact scope, say a 4-12X50’s sitting side by side, one with >AO the other without, i would have to believe that the AO better have a >BIG advantage to make me want to have to deal with the extra adjustment. >So what is AO? Why? When? How? … >Rob
Response:
(Snip) Why would anyone want >to have to mess with two settings? I would have to think that if you >have the same exact scope, say a 4-12X50’s sitting side by side, one with >AO the other without, i would have to believe that the AO better have a >BIG advantage to make me want to have to deal with the extra adjustment. >So what is AO? Why? When? How? …
Rob, You are combining two different seperate and unrelated adjustments into one question. First the power ring should not effect the focus of the scope, only the magnification of the target and the field of view. In hunting situations I prefer to leave it set at 3 to 4 power while big game hunting in the woods and up it to 6 or so if in open country. The higher power is nice to have for target shooting or varmint hunting from a rest. The parallax adjustment is useful for a number of things and if your rifle and load are able to hold less than 0.5 MOA, it will help in your target work. It can also be used as a range finder,. To use it as a range finder first find out how accurate the yardage markings on the scope ring are, compared to a known distance, ie, 100 yds 200 yds 300 yds etc. If you look closely as you adjust the objective at say 100 yards you will see the target blur as you turn it to a less distant or more distant yardage setting. Once you have determined that the yard markings on the scope are accurate, you can then look at a target at an unknown distance and turn the parallax adjustment until the target becomes as clear as possible, then read your yardage setting. This will give you a very good guide for your hold over and for your wind drift calculations. A good scopes parralax adjustment will be quite accurate from about 35 yards to 500 yards, beyond that, on most scopes, you will have to guess as they usally do not have much of an adjustment range between 500 yards to infinity. For target work with an accurate rifle it is absolutely necessary to have a parallax adjustment on your scope, especially when you are grouping in the 0.5 or less MOA range. Hope this answers your questions. Good Shooting to You, Jim Nasset Aftermarket Innovations
