How far forward to mount an AR red dot?

[brewer12345]

I bought an inexpensive red dot to go on an AR that has been sitting in the safe without an optic for like a year. I have never used a dot sight before, so I started fooling around with sliding it forward and back on the rail and saw that the appearance of the dot changed based on where it was on the rail. How much eye relief should I have with one of these? Does it matter?

 

[Skylerbone]

I don't know that it's correct, but further forward gives up less peripheral vision. Mine is mounted above the magwell. Experiment?

 

[grampajack]

It really depends on your personal preference. Obviously you have to work within the constraints of the setup. If you plan on using a magnifier then you might even have to cantilever it. If you just have backup iron sights, then obviously that keeps you from having it all the way back. But yea, if you have the entire rail to play with it's just a matter of preference. I prefer mine somewhere in the middle. A lot of it has to do with your shooting stance and the length of pull adjustment or lack thereof.

 

[badkarmamib]

I don't know that it's correct, but further forward gives up less peripheral vision.

I have mine mounted at the far front of the receiver. My handguard has too much play for me to want to mount it on there, which is frowned upon, anyways. It works for me, and gives room for my flip-up BUIS. YMMV, but a red dot isn't exactly a precision sighting system, find out where it feels comfortable to you.

 

[Varminterror]

It doesn't really matter - the dot will stay roughly the same size as viewed by the shooter regardless of position. The closer you place it to your eye, the better you'll be able to center it in the pane, best eliminating parallax potential, but you'll also cover more of your field of view with the frame. The farther away, the more of the frame the dot will appear to cover, so you might not notice quite as well when your dot drifts off of center - but you'll have a better view of the field.

It's a bit of a personal preference - if you want to minimize your field of view interference, then slide it farther out, if you want to view the field through the optic, slide it back. I like to position mine at the front of the receiver - not on the handrail. I have some offset dot sights mounted on the rail which are pretty far forward - as in in front of my support hand on the handguard, but I've found that to be less than optimal for sight acquisition as well as functional snagging.

 

[Kendal Black]

How much eye relief should I have with one of these? Does it matter?

Doesn't really matter. The lack of any critical distance for eye relief is one of the selling points. I like to place the dot sight far enough forward that it cannot possibly hit me in the eye.

Beyond that consideration, it seems to me that the dot is quicker to find if the sight is not too far forward, because the hole in the rear of the sight looks larger when it is closer. That's simply the other side of the coin to saying the sight subtends less of your peripheral view when you mount it farther forward.

Do to suit yourself.

 

[brewer12345]

Thanks, all. This is intended as home defense, so precision is not a huge deal. I just did not know if there was some standard way of doing it.

 

[imashooter]

No standard but for home defense you'll typically sight the dot more quickly if closer to you. If new to red dots, practice and perfect sighting with both eyes open. You'll pick it up quickly and appreciate the advantages.

 

[brewer12345]

No standard but for home defense you'll typically sight the dot more quickly if closer to you. If new to red dots, practice and perfect sighting with both eyes open. You'll pick it up quickly and appreciate the advantages.

I will give it a try, but my vision has been problematic all my life and I don't see in real 3D just walking around the house. I cannot see sights without closing one eye in most cases. Worth a try with the dot, I suppose.

 

[Klint Beastwood]

I bought an inexpensive red dot to go on an AR that has been sitting in the safe without an optic for like a year. I have never used a dot sight before, so I started fooling around with sliding it forward and back on the rail and saw that the appearance of the dot changed based on where it was on the rail. How much eye relief should I have with one of these? Does it matter?

hollowgraphics you want more forward. forward being more in the middle. they were designed for competition guys on pistols, so they there were designed around the distance between eye and pistol sight, so about middle to more foward on a rifle. red dots are probably similar.

 

[Corpral_Agarn]

I like my Trijicon MRO as far forward as it can go on the upper receiver before the rail begins.

Seems to work well.

ETA pic:

 

[Armored farmer]

Here's my reflex on my 10.5 inch .223. I shoot with both eyes open.

 

[Skylerbone]

I will give it a try, but my vision has been problematic all my life and I don't see in real 3D just walking around the house. I cannot see sights without closing one eye in most cases. Worth a try with the dot, I suppose.

Give this a try: hang a target on the wall and use a lens cap on the front of your red dot. Now, leaving both eyes open, turn on the dot and aim the rifle at your target. Your brain will superimpose the dot on the target for you and you'll get used to shooting both eyes open.

 

[cdb1]

There is a fairly rare condition which I have where neither eye is dominant. I unfortunately wasted a lot of years and ammunition before going to a professional to diagnose my problem. If you have the same issue you can't shoot with both eyes open.

 

[Armored farmer]

I will give it a try, but my vision has been problematic all my life and I don't see in real 3D just walking around the house. I cannot see sights without closing one eye in most cases. Worth a try with the dot, I suppose.

An old trick used by trapshooter is to stick a small strip of scotch tape to the upper portion of the left lens of your shooting glasses.

 

[Sam1911]

There is a fairly rare condition which I have where neither eye is dominant. I unfortunately wasted a lot of years and ammunition before going to a professional to diagnose my problem. If you have the same issue you can't shoot with both eyes open.

This is the beauty of a red-dot optic on a rifle: You CAN shoot with both eyes open no matter which eye is dominant, or if neither is.

As Skylerbone said:

Give this a try: hang a target on the wall and use a lens cap on the front of your red dot. Now, leaving both eyes open, turn on the dot and aim the rifle at your target. Your brain will superimpose the dot on the target for you and you'll get used to shooting both eyes open.

(For a right handed shooter,) You may fix on the target object more firmly with your left eye but by keeping both eyes open you'll still have the red dot right on the target. Your brain puts the images together.



...Just don't forget and try that with an iron-sighted rifle. BIG difference and you'll shoot far to the left because of your left eye aligning the front sight and target, Totally different system at work there.

 

[Creaky_Old_Cop]

I tend to run my dots out to the end of my upper. But it is whatever works best for you. Yes, I run my MBUIS in closer on the rail because I can flip it up and activate my light without moving my hand...

 

[RussellC]

I will give it a try, but my vision has been problematic all my life and I don't see in real 3D just walking around the house. I cannot see sights without closing one eye in most cases. Worth a try with the dot, I suppose.

Well, since you are new to red dots, it is interesting why you want to try both eyes open. An optical illusion sort of thing happens, which is great for indoor defense, or any close quarters work. The red dot will float like you would expect a laser to do. Just experiment, you should see the dot floating out there, letting you avoid scrunching up shutting one eye and trying to see through it like a scope. If you have flip up guards, the illusion will be present even with the front guard closed! Plus, your peripheral vision remains. Magnification seems to mess this effect up, by the way. If your eyes dont let this illusion to work, well I guess this doesnt matter.

Russellc

 

[RussellC]

This is the beauty of a red-dot optic on a rifle: You CAN shoot with both eyes open no matter which eye is dominant, or if neither is.

As Skylerbone said:


(For a right handed shooter,) You may fix on the target object more firmly with your left eye but by keeping both eyes open you'll still have the red dot right on the target. Your brain puts the images together.



...Just don't forget and try that with an iron-sighted rifle. BIG difference and you'll shoot far to the left because of your left eye aligning the front sight and target, Totally different system at work there.

Sorry, I see you already covered this effect, hopefully his eyes will allow this.

Russellc

 

[RussellC]

There is a fairly rare condition which I have where neither eye is dominant. I unfortunately wasted a lot of years and ammunition before going to a professional to diagnose my problem. If you have the same issue you can't shoot with both eyes open.

Does the "red dot illusion" work for you?

I have cross dominance, and one thing I have learned, after years of trying various methods to compensate and talking with tons of other cross dominant folk is that everyone is different, and there is no one fix for everyone. I have had tons of people, some highly trained tell me that the only way I will ever shoot worth a darn is learn to shoot left handed. Bunk. Anyone who tells you they have a one size fits all solution for your problem, I dont care how highly trained, obviously does not have the condition.

I pistol shoot right handed, just bring the gun up to my left eye with both eyes open. Rifle shooting I shoot straight up right handed, and it works for me. So, take everyones advice, but dont take serious any hard set advice about "the only way you can shoot well is" horse feathers. Try everything, find what works for you and your condition. I have tried and tried, I cant hit the broad side of a barn left handed!

Russellc

 

[Chuck R.]

Like some others for a defensive carbine I'll use for HD I prefer to have my optic as far forward as possible to maintain as much peripheral vision as possible:
For an RDS I use cantilever mounts to put the optic as far out over the forearm as I can:





I've used the same setup for a couple carbine classes and a shoothouse and it woks pretty well for me.

Chuck

 

[Kendal Black]

If your visual issues include astigmatism, here is something to be aware of.

 

[cdb1]

This is the beauty of a red-dot optic on a rifle: You CAN shoot with both eyes open no matter which eye is dominant, or if neither is.

As Skylerbone said:


(For a right handed shooter,) You may fix on the target object more firmly with your left eye but by keeping both eyes open you'll still have the red dot right on the target. Your brain puts the images together.



...Just don't forget and try that with an iron-sighted rifle. BIG difference and you'll shoot far to the left because of your left eye aligning the front sight and target, Totally different system at work there.

I cannot shoot with both eyes open using a red dot. I've tried every trick in the book.

 

[cdb1]

I will amend my statement. I can and do shoot with both eyes open using the trick mentioned by Armmored Farmer. My shooting glasses all have a small piece of tape on the left lens that allow me to see everything but the barrel with my left eye. So, I am shooting with both eyes open when using a red dot but actually only seeing the dot with one eye.

 

[cdb1]

Does the "red dot illusion" work for you?

I have cross dominance, and one thing I have learned, after years of trying various methods to compensate and talking with tons of other cross dominant folk is that everyone is different, and there is no one fix for everyone. I have had tons of people, some highly trained tell me that the only way I will ever shoot worth a darn is learn to shoot left handed. Bunk. Anyone who tells you they have a one size fits all solution for your problem, I dont care how highly trained, obviously does not have the condition.

I pistol shoot right handed, just bring the gun up to my left eye with both eyes open. Rifle shooting I shoot straight up right handed, and it works for me. So, take everyones advice, but dont take serious any hard set advice about "the only way you can shoot well is" horse feathers. Try everything, find what works for you and your condition. I have tried and tried, I cant hit the broad side of a barn left handed!

Russellc

It doesn't for me. I'm 58 and have tried everything. Once the tape went over the lens it was incredible how much better I shot.