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Discussion Starter · #1 ·
I figured out I need a different type of site on my new AR. I can't see the iron sights with my trifocals. I just found a Bushnell 3x9x50 scope in my equipment box that I bought years ago that never got mounted. Will this scope fit on the AR and co- witness?
 

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Wow, what a question ! The answer is the dreaded "it depends". If your sights are up higher than the scope would normally be to co-witness it, then you'll need to get taller scope rings or you'll need a riser that will raise the scope up to a certain height. It's a lot of trial and error and finding the right combination of hardware to get it co-witnessed correctly.
 

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Typically I co-witness through 1X sights.
With scopes I mount 45 degree BUIS that function independantly from the scope.
 

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Discussion Starter · #4 ·
Ok, I obviously need to do some more research because I got 2 answers that seem to answer my question but I still don't know. I believe it will require some type of riser because the iron sights aren't removable that I can tell. They're mounted as part of the gas block. It is a Ruger AR556.
 

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If you want to have a co-witness I suggest you try a red dot. If you want to go with a scope on an AR either do like Minga suggests and try an offset set of sights or an offset red dot with your scope, or go to a variable 1 X 4, 6, or 8 power scope for close shots and magnified optics for the long shots.
 

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Co-witnessing with a scope really depends on the hight of the scope rings and where the center of the scope is in reference to the rail. Based on the AR front sight you've shown, I don't think you can pull off the 45 degree offset iron sights. The only way to see if it'll co-witness is to try it.
 

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A slightly More radical approach but common is to cut the front sight down (Dremel) so it is only a low gas block and add/replace a hand guard that can accommodate accessories. This will make the options mentioned (and more) easy to accomplish and change or adjust at will.

That process is is easy, very well documented and more affordable than ever.
 
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So far, my limited experience (the past 5 years or so, 5 or six AR's, and about 10 different types of optics/sights, and combinations thereof) have taught me that pretty much anything not true 1x will blur out your front sight. The higher power you go, the less you will actually even be able to see it at all (at 4x and above it won't obstruct your sight picture). Make sure you get a mount (I use a cheap QD cantilever mount from Amazon that works fine for me and runs about $15) that, height-wise, lets you get a good but comfortable cheek weld on the stock, unless you plan on upgrading the stock to an adjustable number. I usually use 1" height for mine. Anything lower and I'm having to crush my face onto the stock to get a good sight picture.

I ran a Bushnell 4.5-18x on my main AR for a long time (moved it to my AR10) and had a string of different 1-4x, 1-6x and 1-8x optics on it too, which have all migrated to different AR's and a couple found homes on my AK and SKS bullpup...

The .223 cartridge in an AR platform does not have much recoil at all, so you don't really need to spend a TON of $$ on an optic, and if your eyesight is anything like mine, spending too much would be a waste of funds in any case - a top of the line Leupold will not make any better of a picture than a Centerpoint for my eyes ;). The main thing you are looking for is holding zero and a sight picture that is clear enough.

I've shot my main AR with everything from super cheap Amazon 1.5-4x specials to a $300 Primary Arms 1-6x scope and the biggest differences are in holding zero and a little bit of glass clarity at higher magnifications (that I really can't see that well anyway!).

So to your initial question, in my opinion, a 3-9x50 Bushnell will probably work just fine, but with that 50 you will most likely have to mount it higher than is comfortable to get a good cheek weld - and this will raise your sight over bore axis a bit more. At 3x the front sight post will be a dark smudge at the bottom of your sight picture, but at 9x you almost certainly won't notice anything at all.

Chopping down the front sight is an option if it really gets in the way (and I do like the idea of having a staked gas block), but you can also pick up a low profile gas block for under $30. I'd say try it out first and see how it goes.

That's my $0.02:)
 

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To answer one of your original questions: that 3-9x50 scope you found in your box has a 50 mm diameter objective lens. Mounting it on your AR will require that it sit higher from the top of your rifle than a smaller objective lens would need. You might consider buying a smaller scope.

Also, many shooters lean toward putting too much scope on their rifle for its purpose. I'm not saying this is the case for you, just stating a fact about shooters in general. My home-built AR-15 has a 1.5-6x40 scope mounted on it that I find is perfect for me, with rail-mounted BUIS (Back Up Iron Sights) mounted to the same top rail as the scope with a 45 degree offset to the right. Other rifle owners use scopes with more or less magnification, larger or smaller objective lenses. As was stated above, "it all depends."

As far as co-witnessing, I'll leave that to those among us who are more knowledgeable about it than this retired truck driver.

Finally, there is a website from Optics Planet that I find helpful in explaining all of this. Disclaimer: I am not associated with Optics Planet in any way, I just search the internet for good, helpful information and then share it as needed.

https://www.opticsplanet.com/howto/how-to-choose-a-riflescope.html
 

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If you want to have a co-witness I suggest you try a red dot. If you want to go with a scope on an AR either do like Minga suggests and try an offset set of sights or an offset red dot with your scope, or go to a variable 1 X 4, 6, or 8 power scope for close shots and magnified optics for the long shots.
Do give red dot sights some consideration. After trying a few scopes in his AR, my oldest son mounted a red dot sight. He says he'll never go back to a scope on that AR, the red dot is too much fun, accurate, and easy to use.
 
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Do give red dot sights some consideration. After trying a few scopes in his AR, my oldest son mounted a red dot sight. He says he'll never go back to a scope on that AR, the red dot is too much fun, accurate, and easy to use.
These do work with trifocals, but for anything beyond 50 yds and steel targets, I absolutely need some magnification - and the 3x magnifier really is NOT going to help shooting groups. If you're just thinking about slapping steel at 100yds, at least a 10" plate would be recommended with a red dot and a 3x magnifier.
 
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Don't worry about cowitness or lack thereof with a 3-9 scope. You won't see the front sight through the scope other than perhaps a bit of shadow at 3x. Above that it just completely disappears due to focal point or magic or something.

I have a 3-9 Nikon on one AR, so I almost know what I'm talking about.
 

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I'm reading the responses after my post and I agree that this will be difficult to do with a 3-9x scope. I had done it with a Bushnell 1x red dot and I had a really tall riser to accommodate it. I had the same front sight you do, and the co-witnessing was pretty cool but I got to the point where these old eyes need a scope like the one you bought. I had somebody remove the front sight and put a small rail where the sight once was, then I mounted my 2-7x scope and it's much better for me. I have a front sight I can put on that rail on the front and hopefully I can get it where it's pretty accurate when I remove and replace it, I haven't gotten that far yet but I will be soon. Either way, I'm going with the scope I installed and not looking back.
 

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Ho good are your eyes?

:p
Getting worse by the day, I'm afraid.....

.....my astigmatism wreaks havoc on the unmagnified red dot.....but it's still useable.

What I really like about the magnifier is that you can simply flip it to the side when you don't need it.
 

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Just eliminate the irons on the gun and go with optics, better for the hard of seeing, anyway. I have no iron sight on my M4 except the ACOG wannabe I bought for it has an adjustable open sight on top of it for CQB. It works for in the house ranges and has a true-glow insert making it easy to see with the green LED lamp turned on. This scope was only $130 bucks and I got it for 70 because it was the last one the guy had and he'd rounded the adjustment screw off on the elevation to the open sight. New screw and I'm in business. :D I figure he sold it to me at his cost just to get rid of it. It's a good scope, though, works great and has taken some knocks on the ATV with no adjustment changes. I like it even if it's an off brand POJ. :rofl: It's branded "Sniper" and is a Chinese wonder, but then all Bushnells of the Sportview and Banner lines are Chinese and the Banner I bought recently for my SKS is fantastic. Only gripe I have to it is the lighted reticule is so bright it's worthless. But, I don't need that with the green laser I put on it and it's quite a bright scope in dim light anyway. Over the years, I've been very impressed with Bushnell. I have a Bushnell Trophy 3x9x40 on a .22 magnum that is REALLY good, Japanese made. It runs around 150 bucks, was on the gun when I traded for it. If I ever sell that rifle, the scope stays with me. :D The Bushnell Trophy line is very impressive.
 
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I mounted a one inch riser on my AR, and attached a quick release scope on it. I left the front, and rear MBUS site alone. Works way better than I thought it would. I use my rifle with the scope sometimes, and sometimes I don't. The riser I bought was about ten bucks.
 
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