Help: Understanding Scopes

[joker7037]

I have been looking at scopes recently. I have come to the conclusion that I have no idea what I am looking for or at. What do the numbers represent? Example: 3-12x40 or 6-18x40 What is an adjustable objective?
What are some features to look for or avoid? I am looking for a nice entry level scope. Saw some BSAs pretty cheap on SWFA.com. Just confused by the whole thing.

Thanks, Chris

 

[Jack Ryan]

Example: 3-12x40

3x12x40 is a variable power adjustable scope. The first two numbers indicate the minimum power multiplication and the second number is the maximum power setting meaning things will appear 12 times as close looking through the scope as just the naked eye.

The 40 number is the size of the objective lense - the front end of the scope. Generally the larger this number the brighter things will appear, actually meaning you loose less light so you can see through the scope to identify your target in lower light conditions with a 40 mm optical than with a 32.

Parallax sets the scope for the distance the target is from the rifle. IT IS NOT FOR ADJUSTING THE FOCUS. Most scopes 9 power or less will not have this option. They will be set from the factory at 100 yards.

For higher power options the parallax comes more in to play and you can not depend on those yardages marked on the scope on most brands. To see what matters to you as a user in an obvious manner, set a high power scope to the highest setting and support the gun on sand bags so it doesn't move and is on a target say a hundred yards away.

Now look through the scope and notice that the cross hairs move around on the target when you move your eye even though the gun is not changing position. If this is true, the scope parallax is out of adjustment for that range.

Now sit down with the gun to your shoulder so you eye stays aligned with the gun and you can still put a hand on the parallax adjustment and turn it a little. Deliberately move your head just a little and see if the cross hairs stay on target, move more than before, or less.

When your eye can move a little and the cross hairs stay welded to the bull's eye then the parallax is set for that distant target. Look at the yardage setting now and you will get a good idea what it should be next time at a known distance.

...or just stick with lower magnification scopes 3x9x?

To set a scope intitial focus setting (Unload the rifle and leave the bolt open. (just pull the bolt out while you are working it is even better) turn the scope to the highest power. Point the rifle at the blue sky with it to your shoulder in normal shooting position. Look through the scope and if the cross hairs are blurry adjust the focus, the rear ring. Put the gun down and look at the horizon for a few minutes to get your eyes back to normal, they will compesate while you are adjusting. Now repeat the process and if the cross hairs are initially blurry adjust the focus ring again. Do this until the cross hairs are not blurry when you shoulder the gun and look through it at the sky.

 

[joker7037]

Any suggestions on a decent some what cheaper scope. Have been looking at BSA, Simmons and couple others. It would for an AR15 .223, mostly target use, and maybe some varmint. Also what is MOA?

 

[Indy_Guy_77]

Ah... MOA...

I'm sure you'll get a much more detailed explanation later from someone who's much more mathematically inclined than I am.

But, simply, MOA = Minute of Angle.

Minutes are "fractions of a degree". Minute of Angle - Wikipedia, the free encyclopedia

What that all boils down to in the shooting world.... is that at 100 yards, 1 MOA = 1 inch. At 200 yards, 1 MOA = 2 inches. If someone tells you that they have a 1 MOA gun, it means that they can shoot regular groups of roughly 1" diameter at 100yds, 2" diameter at 200yds, 3" at 300 yards, or even 0.5" at 50 yards.

Kind of an ever-expanding wedge of space that begins where you are and extends, literally, to infinity.

 

[VUPDblue]

Any suggestions on a decent some what cheaper scope. Have been looking at BSA, Simmons and couple others. It would for an AR15 .223, mostly target use, and maybe some varmint. Also what is MOA?

Most peope will tell you to avoid BSA like the plague. I'm kinda on the fence about them but do not own one. I would suggest that you look into the Mueller line of optics. They are reasonably priced and very nice. There are several very experienced shooters on this site who turned me onto them and I ended up buying one. Again, it is very nice and worth a look. I got mine from Mizzou Mule Guns

 

[Indy_Guy_77]

Yes, as VUPD has said, lots of people have no love for the BSA scopes. Their "Sweet" scopes tend to be their better ones from what I've read. But I don't know that they make a Sweet 223. I've got a Sweet 22 that I'm pleased with on my CZ...so far.

Lots of folks 'round the net REALLY like Mueller; it seems to be the flavor of the day for the Rimfire crowd. And if lots of folks who put $1000 into a $150 Ruger 10/22 like a Mueller scope...then I'm presuming that it's a pretty good optic.

I do NOT know much about scopes other than what I've gleaned from reading various internet forums. But I DO know that a very good rule of thumb, when it comes to optics, is that you'll get what you pay for. Plenty of folks will tell you that you should spend right around the same money on the optics as you do the rifle itself, if that tells you anything.

-J-

 

[Old Syko]

I do NOT know much about scopes other than what I've gleaned from reading various internet forums. But I DO know that a very good rule of thumb, when it comes to optics, is that you'll get what you pay for. Plenty of folks will tell you that you should spend right around the same money on the optics as you do the rifle itself, if that tells you anything.

-J-

Good rule of thumb. I'm a believer. You wouldn't run kerosene in your new Corvette or racing fuel in your lawn mower.

Welcome! • Mueller Optics


Another good source for optics.


Large Selection of Discounted Scopes, Binoculars, Rangefinders and More!

 

[joker7037]

Thank you, don't know how I missed Mueller nice price and selection.

 

[SERVED_USMC]

Not intending to hijack.

So if I were looking at an aimpoint red dot. If I didnt think I was going to use my 11.5 ar15 past 100yds that often I would want to get a 1moa opposed to a 2moa or more?

Good thread Joker.

 

[abnk]

Read this article: Introduction to High-End Long-Range Rifle Scopes

 

[abnk]

Not intending to hijack.

So if I were looking at an aimpoint red dot. If I didnt think I was going to use my 11.5 ar15 past 100yds that often I would want to get a 1moa opposed to a 2moa or more?

Good thread Joker.

Strictly for accuracy, the longer the distance, the smaller the dot should be. If I had a 11.5" bbl and would not shoot past 100yds, I would choose a 2 or 4 MOA dot.

 

[tenring]

Try here for a lot of info.

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