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View Full Version : WANTED: Info on Co-witness optical sight setup


shopkeep
01-06-2006, 10:28 PM
Sorry to break from all the thunder about the DOJ, but I'm in a tough spot here. See I have an EOtech on my SOCOM-16 and I'd like to move it over to a .223 fixed mag cali legal rifle. But I'm having design decision probs... should I do a co-witness setup or just use a flip-up front sight with it so it doesn't obscure the view from the EOtech?

Anyone here ever try a co-witness setup before on an AR-type rifle? Can you still aim with both eyes open, etc? What are the benefits and drawbacks?

Jon
01-06-2006, 10:33 PM
Well I'll let more knowledgeable members answer your questions. I do know you can't co-witness an EOTech with the Vltor CASV-EL rail system. :( Looks like I'll pick up an Aimpoint to use with this rail.

rastro
01-06-2006, 11:35 PM
If you mount an EOtech on the flatop upper receiver, it won't co-witness.

One option is the A.R.M.S. SIR 50 bi-level which is stepped down over the handguard area to allow a lower mounting position in line with your iron sights allowing you to co-witness.

At the bottom of this review by SMGLee (http://groups.msn.com/TheMarylandAR15shootersSite/eotech1.msnw) from ARFCOM is a pic of an EOTECH mounted on a SIR#50.

I've got mine set up like this and like it very much. Co-witnesses with no problems since it was designed for that. Full field of view, both eyes open, very natural. I have a #40 flip-up BUIS and standard FSB.

*** edited to add ***

There is also the RRA Dominator mount (http://www.rockriverarms.com/item-detail.cfm?ID=AR0125EASSY&storeid=1&image=rrdom.gif&CFID=7616946&CFTOKEN=71499899) which allows you to mount it on the upper and has the BUIS included. It is also a little cheaper than a SIR. :D

Mute
01-07-2006, 9:32 AM
An Eotech does not need a riser to co-witness. If you mount it directly to your flat top the front sight will be just about dead center in your viewing screen and you can have absolute co-witness. If you want most of the iron sights out of your view, then you will need a riser and you can have what is referred to as lower 1/3 co-witness. Check out the Arfcom BUIS FAQ (http://www.ar15.com/forums/topic.html?b=3&f=18&t=206233), it should answer most of your questions.

As to which is better, that's really a personal preference. The front sight in the field of view doesn't bother me, but I still prefer not having it there. You'll just have to try out some different setups to see what works for you.

elmo
01-07-2006, 10:10 AM
i've posted pics of my .223 here somewhere with an eotech.

two ways you can do it.

RRA dominator eotech mount has an a2 rear sight and raises the eotech. (I have this one...mount is about $135)

Yankee hill eotech mount raises the eotech site, but does not come with a rear sight. (mount is about $35)

it will co-witness..actually will raise the eotech sight about 1/4 above the front sight.

TonyM
01-07-2006, 10:53 AM
My $.02:

I had my Aimpoint on one of the rifles setup with my LMT BUIS to co-witness. I really didn't like the setup, it looked "busy" to me when shooting. I use that rifle w/o the Aimpoint now, I only use the irons. Figured I can use the Aimpoint on another rifle or maybe something like that S&W 500 Performance Center... :)

On one of my current builds I am using an Eotech on a Larue mount with PRI flip up front and an MI flip up rear. If the Eotech fails I will remove it from the top rail with the quick release and mount it on one of the side rails on the freefloat tube and I can flip up the irons.

I think I'm going to like the new setup alot better, but we'll see. Good luck with your setup.

glock_this
01-07-2006, 11:04 AM
My $.02258:

I have the EOTech 512 with a GG&G quick release on the RRA Dominator mount (mentioned above). this setup allows you to co-wintess using the built in rear sight on the Dominator and, as TonyM says, I can quick release the EOTech with the GG&G (or leave it in place) and snap it elsewhere if it fails and just use the iron sights. My decision, like you, was whether to get a flip up front as it seems to distract me to sight through the EOTech and see any of that front sight - some I know are not distracted by this at all - but I have OCD and.... anyway, for now, I am keeping the standard ironsight up front as I learn my weapon better, but will likely get a front flip up sight in the future as it seems like a reasonable setup that really opens up the field of view if it distracts you like it does me.

Pablo
01-08-2006, 1:23 AM
My $.02:

Figured I can use the Aimpoint on another rifle or maybe something like that S&W 500 Performance Center... :)

[Homer Simpson] mmm... S&W 500 PC mmm... [Homer Simpson]

So when do we get together to shoot that baby!!!:D

saki302
01-08-2006, 3:17 AM
I personally don't like the co-witness setups and prefer folding front and rear sights. I find it a bit cluttered and distracting to see the iron sights in the reticle.
Did you plan on breaking your EOTech in combat? :D

I have backup iron sights just because they look cool, but the likelihood of me needing them ever is around 0.001%.
I run a leupold CQ/T, so I still have a reticle without batteries- with an EOtech, just run flip sights, and a quick detach rail on the EOTech, so if your batteries die, you can toss off the EOTech, and flip out the irons easily (takes about 4 secs.).

-Dave

MaceWindu
01-08-2006, 8:36 AM
I personally don't like the co-witness setups and prefer folding front and rear sights. I find it a bit cluttered and distracting to see the iron sights in the reticle.
Did you plan on breaking your EOTech in combat? :D

I have backup iron sights just because they look cool, but the likelihood of me needing them ever is around 0.001%.
I run a leupold CQ/T, so I still have a reticle without batteries- with an EOtech, just run flip sights, and a quick detach rail on the EOTech, so if your batteries die, you can toss off the EOTech, and flip out the irons easily (takes about 4 secs.).

-Dave

+1 here....exact same as me...

Mace

Anonymous Coward
01-08-2006, 9:49 AM
http://www.rbprecision.com/rb_precision_ar15_performance_tips_.htm

has some sections on cowitnessing and mounts/adapters.

BigAL
01-08-2006, 10:08 AM
I run an Aimpoint in a Larue Tactical cantilever mount. It co-witnesses in the lower 1/3 which is how I like it. I also prefer a fold down BUIS for a less cluttered view. It's still technically cowitnessed but the rear sight is just folded down.

wayoutwest
01-08-2006, 11:13 AM
My $.02:

If the Eotech fails I will remove it from the top rail with the quick release and mount it on one of the side rails on the freefloat tube and I can flip up the irons.

.

GANGSTA :)

TonyM
01-08-2006, 11:43 AM
GANGSTA :)


Hey, I can't be bothered to stop and look for my carrying case when 200 Zombies are inbound and I've only got my Wife as backup. :p :D ;)

BigAL
01-08-2006, 4:20 PM
Make sure your flip-up front sights at least locks in the up position. Nothing worse than missing your shot because the front sight got collapsed by bumping into something.


I should have clarified only my rear sight is flip up. I still run the stock FSB.

Matt-man
01-08-2006, 9:51 PM
If the Eotech fails I will remove it from the top rail with the quick release and mount it on one of the side rails on the freefloat tube and I can flip up the irons.

It seems to me that you can just leave it on there with any failure that doesn't obscure the optics (e.g. batteries/electronics). I shot a rifle using iron sights through a powered-off Aimpoint, and it worked fine. Am I missing something?

kantstudien
01-08-2006, 10:39 PM
[QUOTE=TonyM]Hey, I can't be bothered to stop and look for my carrying case when 200 Zombies are inbound and I've only got my Wife as backup. QUOTE]

If 200 zombies are after you and your Eotech goes down, you're actually going to take the time to re-attach it to a side rail rather than drop it to the ground? :confused:

;)

saki302
01-09-2006, 2:37 AM
If 200 zombies are after you and your Eotech goes down, you're actually going to take the time to re-attach it to a side rail rather than drop it to the ground? :confused:

;)

Nah- that's the part for your glorious ending- rather then get killed by zombies, he pulls out a grenade, lights his cigarette, smiles, then KABOOM :D

-Dave