Hi, all.

With age and changes in eyesight, I am considering switching to a low magnification (e.g. 3x) prism sight for my lightweight, general-purpose AR needs. It's well understood and accepted that these types of optics work well when shooting at distances of 50-300 yards. But shooting at targets closer than that with a fixed power optic presents challenges. I was wondering what techniques are taught and employed these days to address those challenges. I realize a red dot and magnifier or LPVO is also a popular choice to meet this type of need, but I also like the simplicity, optical clarity, and weight savings of a fixed prism optic. Thanks!

Chris

As is mentioned in another thread, I believe the most important technique for fast, close range target engagement is to learn to focus on the target and use one’s peripheral vision to bring the sight reticle onto the target. I.e., don’t try to find the reticle and then “Okay, where’s the target?” which many people have been conditioned to by the “front sight, front sight,” mantra.

That’s easier and more intuitive with an optical sight, but is somewhat applicable even with irons under some situations.

Thanks for the insight, sigfreund. One of the concerns with the technique you described is the shift in POI. I've read people's reports that a significant shift can occur, even at very close distances. They superimpose the reticle in the dominant eye over the target image they see in the non-dominant eye, and that leads to significant POI shift. Any experience with that?

I started to answer your question and then realized I’d misunderstood what you were referring to, so hopefully this is it.

If we aim a handgun with iron sights held at arms length, it will be possible to see two images of the gun and sights because we’re getting images from both eyes separately. Our brain combines them into one view, but the separate images are not superimposed. In that situation there will be a significant offset of the two images, and yes, if somehow we manage to change which image we’re using to aim the gun without changing which eye we’re using to focus on the sights, there will be a major point of impact shift as well.

I do often change the eye that I’m using to aim with because I’m nearsighted in my left eye and farsighted in my right. When I want a clear view of the front sight of a handgun I use my left eye and move the gun to align the sights accordingly. When I want to see the target clearly and seeing the sights clearly isn’t important, I aim with my right eye.

Some people do have trouble with the double image of the iron handgun sights, but it should be simply a matter of conditioning ourselves to focus on the image that we get with our aiming eye.

None of that applies, however, to using an optical sight on a long gun—at least not normally. When I use something like an Aimpoint, I can see the reticle only with the eye that’s behind the sight. If, for example, I’m aiming with my right eye and then close it, the reticle disappears entirely; I can’t see it with my left eye to aim with. If I want to aim with my left eye, I must shift the gun so the sight is in front of my left eye. Therefore there’s no way to get a POI shift by changing from one eye to the other.

When using an optical sight on a long gun, position it so the reticle can be seen clearly through the sight. Even though both eyes may be open, we’ll see the reticle only with the aiming eye which should also focus on the target. Our other eye will expand our peripheral view of the scene in front of us and help “see through” the body of the sight, but it won’t have any effect on aiming.

Clear as mud?

Thank you for the detailed explanation, sigfreund. That is crystal clear. Your description helped me "visualize" the visual concept, lol.

You're welcome.

At 55 I got away from prism optics because I wanted better eye relief. The prism worked well but just seem to take me longer for target acquisition (probably too much thinking).
For a blackout and 556 I decided to go with a red dot on both and added a 3x magnifier on the 556.
I’m good to 100 on the blackout and 200 on the 556.

quote:

Originally posted by Didls:
At 55 I got away from prism optics because I wanted better eye relief.

Yes, I agree. Most fixed mag prisms have very shot eye relief. That's why I'm mainly considering the TA33 ACOG (3x) or maybe the TA11 (3.5x). The TA33 has very good eye relief. What really made me consider the TA33 was the following thoughtful reviews, comments from other users on another forum, and a few YouTube videos:

TA33 3×30 ACOG Review: The “Gunfighter’s” Optic

Trijicon TA33 – The Most RDS-Like Magnified Optic Available?

Trijicon TA33: The Most Underrated ACOG

Trijicon TA33 Review – Best General-Purpose Optic?


A red dot and magnifier is likely the best option for me, but I'm still curious about a fixed mag prism. Paul Howe (CSAT) uses one on his carbine currently, and his thought process and approach is something I value.

A few months ago, I had a 3x prism on one of my ARs. The Vortex Spitfire HD Gen 2 model. A really good price and I wanted some magnification as all I had was a red dot and an EoTech.
The reticle isn't bad but a touch on the small side. Still, at longer ranges (around 200-300 yards), it was fine. Trouble was close ranges but not to the point it couldn't be done.
7 yards to about 50 required a bit more focus than longer range and also an understanding of the zero you had. I do a 36 yard zero and with an EoTech, it pretty simple at 7 yards. Bottom hash mark and you can land head shots in a credit card sized box all day long. The EoTech was easy as it's a Holographic sight and has excellent eye relief and FOV.
I did the same drill with the Vortex and struggled because eye relief isn't great and also because it's magnified. Not impossible but harder. Took longer even though I don't have a shot timer. Easy to tell though.
I don't have any experience with an ACOG so it's probably better than the Vortex.
Both eyes open is the key to help with any optic and it's easier of course with a red dot or the like.
Cheek weld and the same eye distance/placement also helps with a magnified optic.
Hope this helps.

I've got an ACOG on a 20 inch rifle and discovered that at very close range (7 to 15 yards) the first hold over (which is a big cross right under the chevron) is close enough to make very quick hits on a pie plate. At 25 yards the whole chevron makes a dandy aiming point for a torso. Once it reaches 50 its the point of the chevron and knowing the zero.

I use an offset red dot (think pistol sight size) on two of my rifles. The main optic is for say, 30 yds to infinity. If I need to quickly fire at any yardage less than that, I just roll the rifle over a bit & use the RDS. It's quick & accurate. I have it sighted in at 25 yds. If need be I can use it fairly well out to 100yds if the main optic goes down.

I had a high level of success using an issued ACOG to run through shoot houses by essentially just treating the chevron as a red dot. Both eyes open, focus on the target, chevron center mass and bang. It's not very precise, but it's good enough for minute of torso.

^^^^^ This is the "Bindon Aiming Concept (BAC) & it works. It does require some practice but at close range it is quite effective.
I can do it but at my age, it's just quicker for me to use offset sights. I do use ACOG's on a couple of my rifles but they also have offset sights.

Okay, now I have to ask.

I didn’t pay much attention to the term “Bindon Aiming Concept®” for a long time. In fact I originally thought that maybe the “bi” part of the word referred to using two eyes in some unusual way by ninja level warriors and with only certain types of sights. When I actually looked it up recently, however, I found that the bi is just part of the name of the man who “discovered” the technique. Now I’m confused.

According to the apparently authoritative article I read, the Bindon technique* simply refers to keeping both eyes open when using a nonmagnifying or low magnification optical sight rather than closing the nonaiming eye. Keeping both eyes open when aiming is something that shotgun and handgun shooters have done for probably centuries, and hence my confusion; how was it “discovered” in living memory?

Keeping both eyes open when aiming has several advantages in certain situations.
The first, as I mentioned earlier, is that it extends our peripheral vision from one eye to two. That’s a benefit in tactical/defensive/hunting situations because it allows us to see more of what’s going on in the area, and that’s good when enemies or game might need to be engaged quickly. It also allows us to “see through” the sight body itself to a degree, and that’s an advantage for the same reason.

Not having to squint with one eye closed is also more natural and is less tiring after more than a short time. Plus we don’t have to close the nonaiming eye when it’s time to engage a target so we can just continue to leave it in the relaxed, open condition. That’s why competition rifle shooters who use iron sights often attach something like a card on the rifle in front of their nonaiming eye: They can leave both eyes open and relaxed, and not be distracted by the nonaiming view and image.

On the other hand, aiming with both eyes open works less well with magnified optics. That’s because there is a difference between the magnified and nonmagnified images that our brain must deal with. Someone like a law enforcement sniper will probably have both eyes open while being “on the scope” and just monitoring what’s happening with his potential target, but when it’s time to shoot, many (most? I’m not really sure) precision shooters will close the eye they’re not aiming with.

The different images from our two eyes is also why I don’t like magnifying optics for close distance scanning, as when clearing rooms in a building. I keep both eyes open so as to not intentionally half blind myself, but I want to see the same thing with both eyes. When I first chose a low-powered variable scope for the purpose, I found that even 1.5× magnification was distracting and not suitable.

But to return to the Bindon technique, is there something more to it than simply saying, “Keep both eyes open and use the image of the reticle seen with the aiming eye to aim with”? What am I missing?

* Or “concept”—as if it were a theoretical idea that physicists or philosophers might discuss in scholarly peer-reviewed papers in an obscure journal. But the full original term is also, if we can believe it, a registered trademark of the Trijicon company. (Mirabile dictu!)

quote:

Originally posted by sigfreund:
But to return to the Bindon technique, is there something more to it than simply saying, “Keep both eyes open and use the image of the reticle seen with the aiming eye to aim with”? What am I missing?

I think you're close. I think it's more like saying, "Keep both eyes open and superimpose the image of the reticle seen with the aiming eye on top of the **focused** image of the target seen with the non-aiming eye, and shoot.”

I think that when most people use the BAC terminology, they're really referring to the OEG concept. The BAC intent is to increase the awareness of a magnified optic shooter, as Sigfreund notes. The OEG concept more directly adresses superimposing a reticle over the view of the "non-optic" eye.

You might be right, KSGM. The two concepts are similar and used interchangeably. But in my case, the aiming eye is not occluded, it's just not the eye being used to focus.

quote:

Originally posted by KSGM:
I think that when most people use the BAC terminology, they're really referring to the OEG concept.

Ah. That would make sense, and I may have interpreted the “Bindon” thing the same way myself at one point. The “occluded eye gunsight” became relatively well known to shooters as a result of their being used going back to the 1970 Sơn Tây prison camp raid in North Vietnam. Those sights were reportedly very well received by the Army Special Forces raiders who used them, but only (IMO) because they were the best sights available for close quarters combat at the time. No serious operators use anything similar today. But someone who was familiar with the O.E.G. technology and the fact that it required aiming with both eyes open might have assumed that the mysterious Bindon Aiming Concept® was the same thing.

Shooters and gun owners are notorious for distorting firearms- and shooting-related terms and concepts from their original meanings based on sloppy understandings and simple lazy thinking (or total lack thereof). One person (often a self-styled pundit) misuses a term and it spreads faster than the COVID-19 virus through the shooting community.

Thanks for that perceptive observation.

And when I think about how to use a low powered (3x) prism optic for close range shooting, I see myself looking/focusing on the target (which is possibly moving) with both eyes and raising my rifle up into the line of sight. This is where the OEG concept would take place. Even without the optic being occluded, my brain would naturally remain focused on the non-magnified image in my non-aiming eye because the magnified image is sufficiently different. Yet, my brain would superimpose the bright reticle over the focused image. Thus, resulting in the OEG effect and a good hit on target could be accomplished. I am still wondering, though, how much of a POI shift could result from using this technique out to perhaps 25 yards or so. It may be quite significant.

I believe I better understand your point now, Chris17404.
I don’t have any magnified optics of the sort you’re referring to mounted on guns at present, but it would be an interesting experiment to conduct. I still predict, though, that if you use the illuminated reticle to aim with, i.e., put it on the target, there should be no POI shift.
But you should try it and let us know what you find.