What's so good about 1/3 co-witness?

[MerKWorK]

I just got my Aimpoint T-1 Micro with the Larue 660 which is the tall mount. Okay actually bought 2, I buy everything in 2's because my wife, as my equal, fights by my side. Anywho...We are having trouble getting used to co-witnessing our sights the lower 1/3 of the optic. So someone please tell me as a layman whats so good about this. I liked being able to center all, and not shift my head. Not a huge deal and some trigger time will bring us into our element. Just curious!

 

[jblomenberg16]

The lower 1/3 co-witness among other things gives you a bit more visibility above the iron sights, meaning there is less blocking your view, and you can have more of your target in the sight picture.

 

[MerKWorK]

Thats the one I figured, so what are the others?

 

[esrice]

Co-witnessing is just the how you set things up, you're not shooting with the sights co-witnessed.

First, are you using flip-up or fixed BUIS?

If flip-down, then you simply keep them folded, and look through your optic, at the target, superimpose the dot, and pull the trigger.

If fixed, then you're normally looking over the irons, through the optic, at the target, superimposing the dot, and pulling the trigger.

Then, in the event of an optic failure, you simply tuck your head down a bit and sight with your irons, looking through the optic window.

 

[MerKWorK]

GGG rear BUIS and Samson Assisted front buis. And sure I can fold them out of the way, thats what they are made for. I'm not a noob...just saying, I found it easier and faster(so far) to acquire the rear peep inside the big ghost ring(optic) and front post inside them. Now I have to adjust my head to align the front in rear, offset in the big ghost ring. Just seems like more of a task.

Whatever... have them now, just did realize the difference or the reason behind it. As long as my wife and I can still dominate whatever is in front of the muzzle I'm good!

 

[lovemachine]

I like the 1/3 co-witness. I chose that one because esrice recommended it.
I thought it was going to be weird as hell, but nope. I've gotten very used to it.

 

[dom1104]

Myself, I dont like it so much.

I like absolute co-witness with fixed BUIS.

But thats just how I roll!

 

[ghostinthewood]

I still don't understand. 1/3 is used for more FOV right? Well if you move them to the lower part of you sight, you still dont have a big FOV because the lower part of the glass has less surface area than the middle.

It seems like I'm missing something. Anyone have pics?

 

[dave29]

 

[RichardR]

I prefer absolute co-witness, that way my cheek-weld is always the same, IMHO consistency is key to accuracy.

 

[Clay]

I dislike 1/3 co-witness.

I like to setup my rifle so when I have my cheek weld, everything is where I need/want it. If I put my optic up high enough to put the normal sight picture in the bottom 1/3 of the optic, then I dont have a good cheek weld. Not my style.

 

[KokomoDave]

I think they both suck since all I have is a wrist rocket slingshot.

 

[MTC]

Have a couple questions for an instructor or someone with experience with the various co-witness set-ups.

Looking at those pictures posted above, got crossed up somehow. Was taught originally to use irons, and the sight picture - both for zero and firing center mass - would look like the first picture (minus the dot). Some years later, added an aimpoint with flip-up rear at absolute co-witness height, re-zeroed and verified with dot on then off. Sight picture looks the same or essentially the same when the dot is on, just lowered a tiny amount so that the dot bisects the zero mark while remaining on top of the post. That way nothing really changes, the dot is just a helper.

Last year, changed over to Larue cantilever aimpoint mount with Troy BUIS, but found it puts the irons in the lower 1/3. This is mentally uncomfortable for me, and just looks plain "not right". But since many had said how great it is, I thought 'just deal with it'. So zeroed like before (pumpkin on the post with rear sight folded down). Zeroed separately with irons, but something just doesn't seem right. After looking at that second pic, it seems I might not have zeroed properly.

So my questions are:
1) With a lower 1/3 co-witness set-up, what should the sight picture look like when zeroing with the dot on?

2) With this type set-up, what should the sight picture look like when zeroing using only irons?

3) Will there be a difference in the look (POA-POI) between the two while shooting from various positions or moving?

The reason I'm asking is because the zeroing procedure has been permanently ingrained, and I don't want to unlearn what has been learned. Moreover, when I pick up the rifle and look through the sights, I expect to see the same sight picture the same way every time. The Bindon aiming concept appeals to me, yet I still expect the reference point to be in the center of the sight picture, without substantial changes in the cheek weld.
The answer - if I can get a straight one - may cause me to change back to irons only or low-power fixed, and may help explain why shooting in general is not really that much fun or enjoyable lately.
Tired of tinkering with all these set-ups that are not compatible with each other, or are simply not to my liking.

 

[MerKWorK]

Have a couple questions for an instructor or someone with experience with the various co-witness set-ups.

Looking at those pictures posted above, got crossed up somehow. Was taught originally to use irons, and the sight picture - both for zero and firing center mass - would look like the first picture (minus the dot). Some years later, added an aimpoint with flip-up rear at absolute co-witness height, re-zeroed and verified with dot on then off. Sight picture looks the same or essentially the same when the dot is on, just lowered a tiny amount so that the dot bisects the zero mark while remaining on top of the post. That way nothing really changes, the dot is just a helper.

Last year, changed over to Larue cantilever aimpoint mount with Troy BUIS, but found it puts the irons in the lower 1/3. This is mentally uncomfortable for me, and just looks plain "not right". But since many had said how great it is, I thought 'just deal with it'. So zeroed like before (pumpkin on the post with rear sight folded down). Zeroed separately with irons, but something just doesn't seem right. After looking at that second pic, it seems I might not have zeroed properly.

So my questions are:
1) With a lower 1/3 co-witness set-up, what should the sight picture look like when zeroing with the dot on?

2) With this type set-up, what should the sight picture look like using only irons?

3) Will there be a difference in the look (POA-POI) between the two while shooting from various positions or moving?

The reason I'm asking is because the zeroing procedure has been permanently ingrained, and I don't want to unlearn what has been learned. Moreover, when I pick up the rifle and look through the sights, I expect to see the same sight picture the same way every time. The Bindon aiming concept appeals to me, yet I still expect the reference point to be in the center of the sight picture, without substantial changes in the cheek weld.
The answer - if I can get a straight one - may cause me to change back to irons only or low-power fixed, and may help explain why shooting in general is not really that much fun or enjoyable lately.
Tired of tinkering with all these set-ups that are not compatible with each other, or are simply not to my liking.

Maybe you should have started this thread. You pretty much summed up most of my issues, guess I just didn't spell them out near as well as you. While I haven't yet zeroed my new setup, it just seems to be so different. Almost wrong. Trigger time will tell though!

 

[MTC]

MerK, didn't mean to interfere with your thread. That's been naggin' at me for a while and may have been covered somewhere, but somehow in my case fell through the cracks. Thought it might as well be posted here, and could help others, too.

 

[esrice]

Guys, this thread should help: https://www.indianagunowners.com/forums/accessories_and_gear/43721-ar_rail.html#post475239

And a pic from that thread:

 

[MTC]

Thanks, Esrice for the link with pics. I don't mean to come off like a lousy ingrate, since you're one of the most helpful people I've met here, so please don't take this the wrong way... but that doesn't specifically answer my questions. It might however, explain how and why I was able to run this set-up through a few short carbine courses hitting dead nuts with the dot on, but missing consistently to the same spot using the irons only with the dot turned off.

This is mostly speculation as I'm more frustrated than ever, but instead of that, I'm replaying the memory tapes to find out what happened. It seems that in the heat of the moment, especially while moving and engaging targets using the BUIS only with dot turned off, I might have been using the optic tube as a ghost ring (habit from shotgun and some rifle sights I really like) and putting whatever was available in the center of that ring. This could have induced a type of parallax problem, since they had been zeroed separately using the irons only while consciously ignoring the main optic tube.

Not trying to unnecessarily complicate the issue, but it's still fascinating to get to the bottom of how the eyes work in conjunction with sights. Found this out at great expen$e through messing with binoculars, spotting and rifle scopes from Steiner, Zeiss, Leica, Leupold and Trijicon. When it turns out that certain laws of nature and of physics cannot be changed or bucked, (e.g. the human eye can only focus in one focal plane at a time), I can accept that. When it's all said and done, it may be a stubborn insistence on having two - and preferably three - points of reference in order to properly triangulate on a target. If that is the case, I know that even with increased practice I will never be as fast as the competition shooters who claim - (and I don't doubt them, I've seen them) - that they shoot with both eyes open, sometimes with only a single point of reference. Went to dots in the first place not only 'cause I wanted an uncluttered FOV, but also to try the both eyes open method. It sounds more relaxing, yet in practice the lateral ghosting messes with my eyes. (In line ghosting is fine and actually more desirable to me, yet I still expect the reference point to be in the center of the target, not the six o'clock position.) Maybe it's just a matter of getting used to it.

 

[ghostinthewood]

I'm still a little lost. Haha. Sorry I'm super kinetic.

You have to change your cheekweld for the different sights?

Is there an advantage of 1/3 if you have flip up sights? I mean they're out of the way most of the time anyway right?

The new school of thought is smaller red dots are better since both of your eyes are open so it actually allows for a better FOV. Since with this you plan on using your irons at some point, would that negate that school of thought?

 

[45pro]

wow...i have no idea what any of you are talking about....guess thats why they call me a noob...is there a book for dummies?

 

[Blackhawk2001]

Thanks, Esrice for the link with pics. I don't mean to come off like a lousy ingrate, since you're one of the most helpful people I've met here, so please don't take this the wrong way... but that doesn't specifically answer my questions. It might however, explain how and why I was able to run this set-up through a few short carbine courses hitting dead nuts with the dot on, but missing consistently to the same spot using the irons only with the dot turned off.

This is mostly speculation as I'm more frustrated than ever, but instead of that, I'm replaying the memory tapes to find out what happened. It seems that in the heat of the moment, especially while moving and engaging targets using the BUIS only with dot turned off, I might have been using the optic tube as a ghost ring (habit from shotgun and some rifle sights I really like) and putting whatever was available in the center of that ring. This could have induced a type of parallax problem, since they had been zeroed separately using the irons only while consciously ignoring the main optic tube.

Not trying to unnecessarily complicate the issue, but it's still fascinating to get to the bottom of how the eyes work in conjunction with sights. Found this out at great expen through messing with binoculars, spotting and rifle scopes from Steiner, Zeiss, Leica, Leupold and Trijicon. When it turns out that certain laws of nature and of physics cannot be changed or bucked, (e.g. the human eye can only focus in one focal plane at a time), I can accept that. When it's all said and done, it may be a stubborn insistence on having two - and preferably three - points of reference in order to properly triangulate on a target. If that is the case, I know that even with increased practice I will never be as fast as the competition shooters who claim - (and I don't doubt them, I've seen them) - that they shoot with both eyes open, sometimes with only a single point of reference. Went to dots in the first place not only 'cause I wanted an uncluttered FOV, but also to try the both eyes open method. It sounds more relaxing, yet in practice the lateral ghosting messes with my eyes. (In line ghosting is fine and actually more desirable to me, yet I still expect the reference point to be in the center of the target, not the six o'clock position.) Maybe it's just a matter of getting used to it.

I've used a red-dot sight and a trijicon optic with a triangle reticle. If I don't concentrate too hard (if I'm not thinking too much about what I'm doing), two eyes open seems to work OK in good light. If I try to concentrate too much, I get "ghosting" and have trouble focussing on the reticle/target. Does that sound like it's the same as what you're dealing with?