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-   -   Scope issues (http://www.firearmstalk.com/forums/f18/scope-issues-65636/)

bushmaster74 06-02-2012 01:25 AM

Scope issues
 
Mounted a scope on my bushmaster predator ar15. No matter what scope I mount I run out of elevation adjustment. I shimmed one of the rings .020 but I know it's not a proper fix. Any suggestions?????

locutus 06-02-2012 04:25 PM

There's absolutely nothing wrong with a properly installed shim. I've done several with perfect satisfaction.:) Obviously, a higher mount is the "correct" solution, but I've never had a problem with a shim.

A little blue loc-tite above and below the shim is good insurance, IME.

EagleSix 06-02-2012 04:32 PM

How about some more detail? You are running out of elevation.....by how much at what distance? Can you post a photo of the upper, mount, rungs, and scope? If you have the proper rings (height), properly installed, etc.....there is little reason you should run out of elevation adjustment with all your scopes.

Shims are a quick fix, and can be used with success, but they usually will put things out of whack. They are a cheap fix, sometimes called for, however shouldn't be used if there is a better alternative and it sounds to me, there is something else out of whack with your setup.

.

Snakedriver 06-02-2012 05:37 PM

They make scope mounts for AR-15's (and others) that have additional elevation built into them. :cool:

Here's an example of one that has 20 MOA built into it. There are also others:

http://www.midwayusa.com/product/116249/nikon-m-223-xr-1-piece-scope-mount-picatinny-style-20-moa-elevated-with-integral-1-rings-flattop-ar-15-matte

Txhillbilly 06-02-2012 05:41 PM

What scopes have you tried mounting?
What brand/height rings are you using?
What distance are you trying to sight the scope in?

I've never had problems with any type of quality optics running out of adjustment range mounted on an AR platform.
Post some pics of your setup for us to look at,maybe your just using something that won't work with an AR.

bushmaster74 06-02-2012 06:30 PM

I'm not sure how to post pics on here except on my profile. I've used BSA scopes ( which I know are poor quality ). Bushnell and Nikon and have tried several brands of rings. Nothing over $30 set of rings though. I'm tryin to sight in with a laser bore sighter I'll get some pics today and try to post. Do you guys think putting a 1in riser would help??? Thanks for the help guys

Txhillbilly 06-02-2012 06:44 PM

What height rings are you using. Most AR's require High or Extra High rings for a good cheek weld depending on the scope used.
Personally,I think Laser bore sighters are a joke.The easiest way to bore sight an AR is to remove the upper from the lower,take the bolt out,set the upper on sandbags,and look thru the bore,and center the bore on target at 50/100 yards,and then adjust the scope to the center of the target.
You'll be on paper every time,if you do it right.

EagleSix 06-02-2012 06:56 PM

Quote:

Originally Posted by bushmaster74 (Post 822748)
I'm not sure how to post pics on here except on my profile. I've used BSA scopes ( which I know are poor quality ). Bushnell and Nikon and have tried several brands of rings. Nothing over $30 set of rings though. I'm tryin to sight in with a laser bore sighter I'll get some pics today and try to post. Do you guys think putting a 1in riser would help??? Thanks for the help guys

Txhillbilly beat me to it, so read his and here is some more......

A riser is not the problem, if you can get your eye directly behind and center of the scope, and the objective lens bell doesn't touch any part of the gun....you should be good with the scope height (ring height). Without some detail, we are shooting in the dark trying to help you.

What kind/model laser bore sight are you using? Have you used it before on other rifles and familiar with how it works? What type/brand/model rings are you using?

Your can bore sight the old fashion way. Take the upper off the lower. Rest the upper on a firm rest (such as a sand bag). Set a bulleye out at 20 to 25 yards (use something in your backyard, and get it as far away as reasonable, with a bullseye target or something you can see through the bore of your rifle. Line the upper looking through the bore (chamber end) on the target. Without moving the upper raise you eye to look through the scope. Adjust the elevation and windage until the cross hairs of the scope are on target, and without moving the upper, when you look through the bore, the bore is aligned with the target.

If you are doing this for the first time, give it time, as if you move the upper even a slight amount going from looking through the bore and the scope, you may need to go back and align it again.

Also, your adjustments will be backward......example: line up the bore on the target. Look through the scope and if the cross hairs are high on the target......adjust the turrets high (as in moving bullet impact up).

This method of bore sighting will get you on paper at 25 yards (which is the best the laser bore sight is expected to do) so you can make the final zero adjustments with live fire, at the distance of your choice.

I would take out the ring shim.....it's only going to make things worse in the long run, and you certainly don't want to shoot with a shim in the rings. Unless your shim is under the rings between the bottom of the ring mount and your receiver bases......in which case take it out anyway.

More details and photos in your profile will work.....

.

bushmaster74 06-02-2012 06:57 PM

I'm using 1 inch rings right onto the flat top of the rifle. I have a 1 in riser. Should I install that also. Yeah I'm not sure bout the laser sighter either. First one ive purchased

EagleSix 06-02-2012 07:02 PM

Quote:

Originally Posted by bushmaster74 (Post 822769)
I'm using 1 inch rings right onto the flat top of the rifle. I have a 1 in riser. Should I install that also. Yeah I'm not sure bout the laser sighter either. First one ive purchased

What is the height of the 1" rings? Yea, by all means, go ahead and put on the riser, if that allows you to see through the scope better......otherwise, no leave it off.

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