True Co-witness or Lower Third?

[Smith97z71]

Sorry if this is the wrong section but curious what you guys prefer. Leaning towards an Eotech for my latest build and trying to decide what setup. I was thinking about the lower third so if I had my Irons set up for one range, then the smaller Diopter for another, and the Eotech for another. Or will this simply just not work how Im thinking? I also wondered then if this would make the site too cluttered and slow down target acquisition. So now I'm torn. What do you guys think?

 

[mateofeo85]

I think you're gonna get a lot of mixed feedback. But since you're asking for personal preference, I prefer absolute cowitness. I tend to pick up the irons through my Aimpoint or Eotech faster when it's dead center of the optic window, rather than offset in the lower 1/3.

I do completely understand the reasoning for using the lower 1/3, but again, this is just my preference for sight acquisition.

Matt

 

[TravisP]

I agree with mateofeo85. My back up sights on my setup are there just in case my red dot quits. I run an aimpoint. I want my sight to be in the same place as my dot would be.

 

[Drifter™]

Absolute co-witness is my preference after trying both ways.

 

[Katahdin]

Lower third for me. I like the FOV of just my EO Tech, I have run a EO Tech 512 (true co-witness) and EO Tech 553 (lower third) with my fixed Larue rear sight and A2 sight post. With lower third the rear sight is still usable if need be, just bury your cheek into the stock a little more to look through your irons, for most of my shooting I like using the red dot only.

If you are going to zero your irons and red dot at separate distances and you go true co-witness then you will see two different sight pictures and it will probably mess you up.

 

[Katahdin]

REMEMBER, when you look through your irons (lower third) you will still see your red dot on the tip of your front sight post just like you would if you had true co-witness, you just have the option of using your red dot only for CQB distances which I find is faster than true co-witness.

 

[DirtyRod]

Lower 1/3 for me.

 

[Joe Curnarski]

Lower 1/3 for me. I run an Aimpoint T-1 with my BUIS in the lower 1/3. I have never experienced a failure with the Aimpoint in five+ years, but remember Murphy's Law! I keep both my front and rear sight down on my work carbine and run just the red dot. With the front sight in the "up" position my field of view is "too busy" for me. I prefer just the red dot out there for target acquisition.

Some persons whose opinions I trust run with a fixed front sight or with the folding front sight in the "up" position. Should the red dot go south, at close range they merely use the Aimpoint or EoTech as a large "ghost-ring".

This works for me. Your mileage may vary.

Good luck.

Joe

 

[Smith97z71]

REMEMBER, when you look through your irons (lower third) you will still see your red dot on the tip of your front sight post just like you would if you had true co-witness, you just have the option of using your red dot only for CQB distances which I find is faster than true co-witness.

This is kind of what I was thinking. I was looking through my brothers Eotech last night which is a true cowitness and still wasn't sure. Im possibly going to buy a EXPS2-Opmod from a member of another forum member. This sight does a lower Third Co-witness. If by chance the lower third bugs the hell out of me, is there a riser mount to make it a true co-witness?

Edit,
Had a derr ta derr moment and just realized after posting that a riser would make a lower third sight even lower. That is unless it has a mount for the rear Iron as well. Do they make such a thing that is an integral mount for both the EOTECH and the rear Iron?

 

[elfster1234]

Id just get a low powered 1-4 or 1-6 scope but thats just me.

If i had to go with a red dot, then it would be 1/3

 

[Blowby]

Good points in both camps and you will figure out what works for you.

I have settled on lower 1/3 on all my AR's using CompM2's. All have fold down rear and most have folding fronts. The ones without fold down fronts the 1/3rd keep any ghosting in the lower section if noticed at all and a large section of real estate un-obstructed. I keep all AR's set up in a consistent configuration so when I grab one my mind is on the task. The only time I use the iron and Aimpoint simultainiously is when I need the dot to sharpen up for critical shots where time is on my side.

 

[CK_32]

I'm a 1/3rd guy

Allows me to use the scope by it self, or together with my irons. Absolute your stuck with one option really.

 

[Katahdin]

Most of the EO Techs are now set up with lower third co-witness, I am pretty sure if you buy and EO Tech with a throw lever mount it will be 1/3 and a thumb screw mount will be set up for true co-witness. I have not bought an EO-Tech for about 3-4 years so I may be wrong. I still have my 512 but I run it with a fold down rear sight, my 553 has my larue fixed back up sight. If you go 1/3 and hate it, I think your only option is to sell it and find one that allows true co-witness. You can go true co-witness and buy a riser for the optic to make it 1/3, but I don't like that one bit.

 

[45.308]

Re open this please. I was all set for absolute but I youtube and after seeing lower 1/3, I think this is my way. Less clutter and it seems easier to use irons, eotech or both. My shot guns are set up similar to 1/3 as I use the front post with red dot lollipop, no rear sight and I like but its a shot gun.

What confuses me is, how or what is zero with relationship between irons and red dot using lower 1/3? I guess am I over thinking, but with 1/3, does the dot sit above or on the front sight as the yourtube lead me to believe it sat on the front site not over it? What am I missing?

Running eotech EXP S2 with Troy battle sights if that matters. I am not an operator, LE or wanna be just a shooter that wants things easy / easier...maybe zombies . I was issued M16 on active and not had one since but....its a new day!

thanks

 

[Sterling Shooter]

Considering the reality when the dot sight is mounted at a height which yields a proper stockweld, the co witness concept is moot. This is as it should be since the benefit to co witnessing is only to discern having maintained a zero on the dot sight. This is not an issue unless the rear iron is fixed such as when using a Daniel Defense type A1 sight. This sight forces the shooter to look over it when using the dot and thus the dot is not quickly resolved which defeats its purpose. On the other hand, looking through the irons to see the dot makes me wonder why have the dot at all. Bottom line, absolute co witness is the way to go using a flip rear sight, something like the Matech. Don't buy into any saying its not fast enough. If you are really concerned that the dot will fail while using it a short range then take it off and use irons. Remember the real value of a dot is there's nothing to align and no need to have focus on the sight. It's a godsend for folks who do not know how to align iron sights or who cannot focus on the front sight.

 

[45.308]

Right now I only run Troy battle sights, DAO rear and do not care what any one says, I like them. Very fast and accurate for me. Personally I really see no reason why not run nothing but the irons as I have but those around me all run electronic dots so I have to join the gang.

I have Eotechs and was thinking why not on the AR so, the 7mm riser was what I was thinking for lower 1/3.

So it is not correct to use red dot with just the front, rear down? Why not keep the rear up just like fixed? Am I missing something by thinking too much?

Not saying much but most of the interweb I checked predominately say lower 1/3 but I know how the interweb is.

thanks

 

[Sterling Shooter]

Right now I only run Troy battle sights, DAO rear and do not care what any one says, I like them. Very fast and accurate for me. Personally I really see no reason why not run nothing but the irons as I have but those around me all run electronic dots so I have to join the gang.

I have Eotechs and was thinking why not on the AR so, the 7mm riser was what I was thinking for lower 1/3.

So it is not correct to use red dot with just the front, rear down? Why not keep the rear up just like fixed? Am I missing something by thinking too much?

Not saying much but most of the interweb I checked predominately say lower 1/3 but I know how the interweb is.

thanks

Start here: What is the purpose of the sight? It gives recognition for where the barrel is pointed. To have this understanding using irons the eyeball must be positioned to where the tip of the front sight post appears to be centered in the rear sight aperture. This alignment is anchored with a consistent stockweld. After alignment the shooter will adjust NPA to get the desired sight picture and then pull focus back from target to front sight. Only when the rifle is properly pointed with consistent sight alignment will the shooter hit where aimed. Now, with a dot sight there is no need to align anything and there is no need to focus on the sight to be able to hit where aimed. So, for any who do not get good hits with irons due to their inability to use them properly the dot sight is a godsend when adjusted for something like a 300 meter BSZ. You could use such a sight without ever missing an as issued BDC iron sight as long as distance to target never exceeded 400 meters. At any rate, for those who are able to properly align iron sights, and are able to focus on the front sight, there is no reason for a dot sight. And if the irons are the as issued type, A BDC function is possible too, which is at best clumsy with dots having such a feature.

O.K. now knowing that all we want to do is know where the barrel is pointed what is best? I'd say if you are hitting where aimed with irons, then there is no point for the dot. On the other hand if you can't get a hang of how to use irons the dot would be better.

Now, assuming the dot is better but you feel it might fail while in use the idea of a BUIS is a pretty good idea, and since such BUIS will always be mil spec height the dot sight will need to be mounted at a height similar so as to allow proper use of the irons if using irons while dot sight is attached to rifle. If the dot is higher or lower not allowing for absolute co witness then problems come about due to perspective of aim issues with the irons which will result in a miss.

 

[rw496]

1/3 because it fits my head

 

[45.308]

Got it figured out, was over thinking. I am a visual learner.

Now I have an Eotech EXP S2 for sale.

thanks