A2 sight/ Eotech
- Thread starter ffgats
- Start date
The iron sights will not cover the dot… when you have it lined up you can see all three and you can line it up so the red dot appears to be above the iron sights.
An XPS will give you true co-witness… the EXPS will give you 1/3 co-witness.
With 1/3 co-witness the red dot sight is raised (notice the extra height of the quick detach) so the iron sights are in the lower third of the window. Google image search it, you will see what I mean.
As for the EXPS vs the XPS… its pretty much personal preference as the only difference is one is higher then the other.
An XPS will give you true co-witness… the EXPS will give you 1/3 co-witness.
With 1/3 co-witness the red dot sight is raised (notice the extra height of the quick detach) so the iron sights are in the lower third of the window. Google image search it, you will see what I mean.
As for the EXPS vs the XPS… its pretty much personal preference as the only difference is one is higher then the other.
Assuming you are talking about a flat top upper and a fixed A2 front sight… Your decision maybe swayed by what type of rear sight you want to use. For fixed iron sights front and back I would suggest 1/3 co-witness. For a folding rear sight I would suggest true co-witness. But really, it is up to personal preference. You could have no rear sight.
If the sights are cowitnessing, you can just zero one of them (typically the optic, since that's your primary) and then align the other to match. It won't be 100% perfect but should be pretty close. You should make sure you have a proper, consistent cheek weld when zeroing the optic and also when checking the cowitness, so that you have a consistent viewing angle, otherwise you could be off if you had your head up when viewing the optic but lowered your head when viewing the irons.
For extra points you can zero the irons independently. FWIW, the adjustment graduations on my MBUIS are not fine enough that for me that made sense to do though. I could not align the MBUIS to perfectly match where my EoTech dot was as the irons simply won't adjust that finely. They are not high precision tack driving sights, they are, well, backups. You'll have to decide for yourself if you want to bother trying with your setup.
I hope this makes sense to you…
The Eotech is a reflex sight, meaning you can look through the window at any angle and if you can see the dot it will be on the point of impact. The dot moves as you move your head, so it always lines up to the point of impact. The front sight does not move; you can only line up your irons one way for point of impact. If you move your head the fixed front sight will no longer be on point of impact, but the red dot will move to stay on point of impact. This is all in relation to your point of view.
So yes, by design the sights can be misaligned per say. If you zero everything together, when you look through the irons the dot will align with them (true or 1/3 co-witness). When you don’t look through the irons the dot will move to align to point of impact. In any event you can just move your head so the red dot lines up with the front sight post. If you adjust the windage on the irons (usually only adjusted on the rear sight) you will have to adjust the windage on the eotech also.
In all reality it comes down to how you feel most comfortable shooting, not how cool your rifle looks. Try it, you may never notice the front sight and block it out of your vision, it may annoy the hell out of you. You can always remove the front sight afterward. Many people run Eotechs with A2 front sights; it has its advantages and disadvantages.
This got longer then I intended… but I wanted you to be clear on what is happening here. If you have any more questions please ask. Maybe look up the wiki for Reflector Sight and look at the little animation…
The Eotech is a reflex sight, meaning you can look through the window at any angle and if you can see the dot it will be on the point of impact. The dot moves as you move your head, so it always lines up to the point of impact. The front sight does not move; you can only line up your irons one way for point of impact. If you move your head the fixed front sight will no longer be on point of impact, but the red dot will move to stay on point of impact. This is all in relation to your point of view.
So yes, by design the sights can be misaligned per say. If you zero everything together, when you look through the irons the dot will align with them (true or 1/3 co-witness). When you don’t look through the irons the dot will move to align to point of impact. In any event you can just move your head so the red dot lines up with the front sight post. If you adjust the windage on the irons (usually only adjusted on the rear sight) you will have to adjust the windage on the eotech also.
In all reality it comes down to how you feel most comfortable shooting, not how cool your rifle looks. Try it, you may never notice the front sight and block it out of your vision, it may annoy the hell out of you. You can always remove the front sight afterward. Many people run Eotechs with A2 front sights; it has its advantages and disadvantages.
This got longer then I intended… but I wanted you to be clear on what is happening here. If you have any more questions please ask. Maybe look up the wiki for Reflector Sight and look at the little animation…
