Red Dot Mounting Choices

[alamo5000]

I have never really ran a red dot on anything so I am asking the guys with a bit more insight and experience to share their opinions.

Here is the question...assume I pick a really good red dot, lets say an Aimpoint T1 or something along those lines. However I see there are several different ways to mount it. I see people mounting them at all different places along the rail at all different heights. Specifically I am asking about a 1x with a 4 moa dot, but no need to limit the discussion to just that. What about dots with magnification? Would they be done any differently?

The discussion or opinions I would like to have is why you put your mounts where they are and why did you pick the height you picked?

I am sure a lot of it is preference but are there merits to doing it one way vs another?

I see people with their dots right on the rail. I also see people with tall mounts. Basically the two parameters are height and placement.

My thought is that shooting with a 1x dot in a dynamic environment is a different school entirely than shooting with a scope.

Thanks!

[Joelski]

Eye relief isn't as important on a red dot as it is with a scope. Also, hight above the bore isn't as critical either; YMMV. You spend good cake on a primo optic, don't go cheap on the mount. With better mounts you gain the ability to return to zero when removing and replacing teh optic on your rail, given you put it in the same place. Lesser oprics have a decrease in this ability, and the mount plays a role.

Let me qualify that with I have always used red dots and am only just now moving into higher quality optics myself, at this point in my life, its not a career influence, more an enthusiast/financial one. :)

[alamo5000]

Eye relief isn't as important on a red dot as it is with a scope. Also, hight above the bore isn't as critical either; YMMV. You spend good cake on a primo optic, don't go cheap on the mount. With better mounts you gain the ability to return to zero when removing and replacing teh optic on your rail, given you put it in the same place. Lesser oprics have a decrease in this ability, and the mount plays a role.

I don't go cheap. That's my downfall :) As for right now I am really not asking about specific mounts as in brands or whatever. I am asking about the school of thought behind where and how high you mount that kind of an optic and why. It's more of an abstract question sort of.

[Joelski]

Gost is right about barricades: nothing beats the big window on an EOTech for inching around a corner to get a peek at a bad guy.

[Joelski]

My preference for lower third co-witness emerged simply because the less cramped I can be, the better. I'm 6'-4" with a neck fusion, so I don't scrunch down like a wee folk! :D

[alamo5000]

My preference for lower third co-witness emerged simply because the less cramped I can be, the better. I'm 6'-4" with a neck fusion, so I don't scrunch down like a wee folk! :D

So you're telling me you're an ogre? LOL!!!

I'll bet you could scrunch down and hide behind a fire hydrant if you needed to! LOL!!!!

[GOST]

I like to use 1/3 height mounts for my RDS's. As for where you mount your RDS that's just personal preference. Some of the options with smaller objective lenses if they are mounted far out make it slightly more difficult for me to acquire the dot. The T1 is a great optic but I prefer a RDS with a larger objective lense, especially when shooting around barricades.

[alamo5000]

I like to use 1/3 height mounts for my RDS's. As for where you mount your RDS that's just personal preference. Some of the options with smaller objective lenses if they are mounted far out make it slightly more difficult for me to acquire the dot. The T1 is a great optic but I prefer a RDS with a larger objective lense, especially when shooting around barricades.

Let's say you are shooting around barricades or are in a hallway trying to take out a bad guy... does not only the optic, but the height and placement of that optic have any bearing? I assume as you infer that a lot of this question does matter about the specific optic, but I am just trying to get a general sense of it.

I would also think it matters what kind of a stock you use as well. If I were to put an optic of any kind right on the rail I would have to raise the gun off my shoulder to get a site picture....

[GOST]

Let's say you are shooting around barricades or are in a hallway trying to take out a bad guy... does not only the optic, but the height and placement of that optic have any bearing? I assume as you infer that a lot of this question does matter about the specific optic, but I am just trying to get a general sense of it.

I would also think it matters what kind of a stock you use as well. If I were to put an optic of any kind right on the rail I would have to raise the gun off my shoulder to get a site picture....

I think that it would be best for you to get time behind different RDS setups. Picking an RDS and mounting preference isn't a science but finding what fits you best. What fits me may not work for you simply cause everyone is built different. If we all took our advise from the pics of a lot of instructors, most of us would be running T1's mounted as far forward as possible. This setup feels great in a shop to me, but isn't my preference. You're a bigger part of the equation than the mount, stock, RDS and mounting preference; can't make a science experiment out of everything.

[Pyzik]

I never realized just how small of an objective lens the micros have until I started shooting my scoped AR more.

I'll agree with GOST that putting it closer to your face helps you pick it up quicker and will also helps reduce the parallax that red dots can have.
As far as height, if you're not running a fixed front sight I'd say go with an absolute mount, if you're going with a fixed front sight go with lower 1/3.

Since you don't go cheap, get the best QD mount you can.

Those are my $0.02. Which probably isn't even worth that since I am not nor have I ever been an operator.

[Hmac]

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I'll agree with GOST that putting it closer to your face helps you pick it up quicker and will also helps reduce the parallax that red dots can have.
As far as height, if you're not running a fixed front sight I'd say go with an absolute mount, if you're going with a fixed front sight go with lower 1/3.

Parallax will be increased the closer you move an RDS to your face. OTOH, it will be easier to pick up the dot in less-than-optimal cheek welds. The trade off is that a consistent and repeatable cheek weld will be critical to minimizing the effect of parallax on POI. Best option IMHO is using an RDS with a 30mm tube (skip the micros) and moving the RDS far enough forward to allow mounting your BUIS and a magnifier. Best combination of rapid dot-acquisition and minimal parallax. (Parallax is not very great at 50 yards with most high-quality RDS and won't affect head-shot accuracy to a significant degree)

My preference is lower-third. All my rifles are set up the same way so I can use the same magnifier on several different rifles, but I've only mounted iron sights of any kind on a couple of them these days. I think they are unnecessary for my shooting needs, and, for me, an unnecessary complication and expense.


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[Pyzik]

Parallax will be increased the closer you move an RDS to your face. OTOH, it will be easier to pick up the dot in less-than-optimal cheek welds, but the trade off is that a consistent and repeatable cheek weld will critical to minimizing the effect of parallax on POI. Best option IMHO is using an RDS with a 30mm tube (skip the micros) and moving the RDS far enough forward to allow mounting your BUIS and a magnifier. Best combination of rapid dot-acquisition and minimal parallax. (Parallax is not very great at 50 yards with most high-quality RDS and won't affect head-shot accuracy to a significant degree)

My preference is lower-third. All my rifles are set up the same way so I can use the same magnifier on several different rifles, but I've only mounted iron sights of any kind on a couple of them. I think they are unnecessary for my shooting needs, and, for me, an unnecessary complication and expense.

You're correct on parallax, thank you for the clarification!

[alamo5000]

Parallax will be increased the closer you move an RDS to your face. OTOH, it will be easier to pick up the dot in less-than-optimal cheek welds. The trade off is that a consistent and repeatable cheek weld will be critical to minimizing the effect of parallax on POI. Best option IMHO is using an RDS with a 30mm tube (skip the micros) and moving the RDS far enough forward to allow mounting your BUIS and a magnifier. Best combination of rapid dot-acquisition and minimal parallax. (Parallax is not very great at 50 yards with most high-quality RDS and won't affect head-shot accuracy to a significant degree)

My preference is lower-third. All my rifles are set up the same way so I can use the same magnifier on several different rifles, but I've only mounted iron sights of any kind on a couple of them these days. I think they are unnecessary for my shooting needs, and, for me, an unnecessary complication and expense.


.

Thanks for that information. I will have to read it more clearly when I am more awake.

I thought an Aimpoint T2 was 'parallax free' though? Or is that just 'has less parallax'?

I will definitely revisit this thread once I start getting the gun together.....

(BTW I have the T2 already just not on an assembled gun)...

[Hmac]

Thanks for that information. I will have to read it more clearly when I am more awake.

I thought an Aimpoint T2 was 'parallax free' though? Or is that just 'has less parallax'?

I will definitely revisit this thread once I start getting the gun together.....

(BTW I have the T2 already just not on an assembled gun)...

Marketing hype.

Eotech, like Aimpoint, uses a collimated image, so parallax is a negligible issue with either, but neither is parallax-free. With Eotechs, the dot image is projected at 100 meters, with Aimpoints, 50 meters. So, both have potential parallax error that is equal to the size of the optical window at zero distance and decreases to zero parallax out at their respective set distances. With either optic, even a crappy cheek weld makes parallax relatively inconsequential in a combat sight.

The closer an RDS is to your eye, the larger the potential angle it subtends between your eye and the projected dot, giving you a greater potential parallax error. Again, bearing in mind that even at its maximum it's a pretty small error from a practical standpoint.

[Joelski]

I'd say it's pretty much what you're comfortable with as far as how high and how far forward. The height is often dictated by a blend of what you can see shouldered vs. un-shouldered and with a cheek weld. The farther forward you can tolerate, the better your two eyes-open sight picture will be: ie less interference from the barrel of the optic.