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SinnFéinM1911
04-12-07, 10:56
Now, I have around this business for a bit now, on both ends of the spectrum, from the .mil side to the industry side.

I think there is common misconception on what Co-Witnessing really is, as to a true definition. Now I am going to put it to the people without my 2 cents and see what the public says Vs what the operators and shooters tend to say (and I will say that there are Tier 1 Operators that do not agree also on this very topic).

This term is thrown around so loosely without a true "text book" definition.

So here it is:

Co-Witness is -

A - Having the ability to be able to align your Iron Sights or BUIS through your Optics / Red dots (where it locates in the glass it does not matter {middle / bottom 1/3}), leaving your red dot Zeroed.

B - Sighting in your Optics / Red Dots and then bringing your Iron Sights or BUIS to align with the Red Dots.

Erick Gelhaus
04-12-07, 11:08
Brett-
No argument with you ... "but" ... what I normally hear folks say is that they've zero'd their irons and have now "co-witnessed" their optics/red-dots/etc to their irons or visa-versa.
I take this to mean that their Dots & Irons will be POI/POA together.

... make sense?

My default is quite different .... my Dot is where it is; my Irons are where they are - because they are different systems.

Erick

rob_s
04-12-07, 11:16
I zero seperately and then check. If they align I'm good to go. So far they've always aligned, so I'm not sure what I'd do if they didn't.:D

I tend to use "co-witness" to verify that the sights and dot are both still zeroed. If I pick up the gun and look through the iron sights and optic at the same time and find that they line up, chances are about one in a million that they both got knocked out of alignment to the exact same point.

At the end of the day though I'm not sure that it matters what you call it or what you use it for as that's really just a matter of semantics and personal preference.

ISAIAH53
04-12-07, 11:18
I take this to mean that their Dots & Irons will be POI/POA together.

I am relatively new to optics on anything. I keep thinking my eyes are young enough to still use irons (on that account, I am mistaken). Anyway, what Erick says is the way I understand it, regardless of whether the top of the front sight post and your red dot are visually coincidental, or located in different quadrants/thirds/whatever of your field of view.

Snake RAH
04-12-07, 11:30
Choice A is the definition I use.

I do the zeroing backwards from you guys. I zero with irons, then put the dot on top of the front sight post, almost like a boresight. I then shoot just optics to verify or set the optic to shoot same POA/POI as the irons.

DrMark
04-12-07, 11:59
I've always considered "co-witness" to indicate that the optic's red dot is co-located with the aligned sight picture, that is, your red dot is on top of your front post when the sights are aligned.

Co- means together, and witness is a reference to what you see, and I take co-witness to mean that your sighting indicators (aligned sights and red dot) are together (in the same place).

My irons and my EOTech do not co-witness, because I run a LaRue EOTech riser. Of course, I can still use my irons through the EOTech window, but my aligned sight picture is not in the same place the red dot is.

I'm not calling anyone else wrong, just explaining how I use the term.

tiger seven
04-12-07, 12:11
Co-Witness is -

A - Having the ability to be able to align your Iron Sights or BUIS through your Optics / Red dots (where it locates in the glass it does not matter {middle / bottom 1/3}), leaving your red dot Zeroed.

B - Sighting in your Optics / Red Dots and then bringing your Iron Sights or BUIS to align with the Red Dots.

Option A is what I refer to when I use the term "co-witness." It just means that you can align your front and rear iron sights though the optic, should the optic fail, eliminating the need to remove it in order to transition to irons. Normally, the irons would sit in the lower 1/3 of the FOV.

Option B is something I have heard referred to as "absolute co-witness" in order to distinguish it from Option A.

Like Erick said, my dot (or reticle) is where it is and my irons are where they are, because they are different systems. I zero the two separately. If I'm using an optic (in my case an EOTech + LaRue mount) the iron sights might as well be invisible to me. I should be seeing only on the reticle and the target. If I am using irons, the optic is either off the weapon or inoperable, so there is no reticle in my FOV. That approach seems to work for me, but I have limited experience and am a long way from being an expert. If I am mistaken or misinformed, please let me know.

Derek

LOKNLOD
04-12-07, 12:36
Choice A is the definition I use.

I do the zeroing backwards from you guys. I zero with irons, then put the dot on top of the front sight post, almost like a boresight. I then shoot just optics to verify or set the optic to shoot same POA/POI as the irons.

This is how I do it also. It seems a lot easier to bring the dot to the irons, than the irons to the dot.

This is how I learned it: Co-witness is being able to align one's iron sights through the optical window, the two common setups being "Absolute" co-witness (recticle centered in optic, irons centered in optic) and "lower third" co-witness (iron sights are visible in the bottom of optical window, when recticle is centered, irons will be below the recticle and less intrusive to sight picture). With the commonly co-witnessed sights like Aimpoint and EOTechs, the dot will still align (enough for social purposes) with irons when you change your line of sight to take the iron sight picture, because they are (mostly) parallax-free. Alignment is assuming the optic and irons are sighted in for the same POA/POI, but that isn't a requirement (although I don't know why you wouldn't).

The whole point is that if the optic were to fail, and you suddenly had no recticle, then your irons would be visible through the optical window and the transition would be as quick as possible without a drastic change in head positioning or needing to manipulate anything mechanically.

Mojo58
04-12-07, 13:45
I zero with the irons and then bring the dot to the same POI.

SinnFéinM1911
04-12-07, 14:01
Here are a few of the comments (not verbatim) from the operators I have talked to in the last 9 months:



Co witnessing is zeroing your Red Dot and Adjusting your Iron Sights to that point.

Argument to that is this:
Iron Sights and Red dots DO NOT print the same on a 25M zero target so if you adjust them separately @ 300m your will not have the same POA/POI. (This is why SOPMOD has offset Targets)





Iron Sights Should naturally co witness, so the term does not apply if optics / Red Dots are not being used as a 3 part alignment. (Rear sight to Red Dot to Front Sight Post)

Argument to this:
Well, I just want to be able and see them through my optic / red dot and thats why they call use that term, and it sounds better.

graffex
04-12-07, 14:19
I dont think there is a right or wrong way. It just comes down to personal taste.

SinnFéinM1911
04-12-07, 14:35
The only reason I am taling about this, is because the are specs and requirments being driven on of this term "Co-Witness" and no one can agree on what it is and most will argue until they are blue in the face that there's is the one "TRUE" meaning of co-wintessing.

Robb Jensen
04-12-07, 14:47
I thought the term co-witness meant that looking through your optic you could align the irons, preferably in the bottom 1/3 to 1/4 of the window. Some guys like their dot sitting right on the front sight post. To me that way is distracting.

Here's how I do mine:
I zero my optic 50yd POA/POI, turn it off. Then zero my irons 50yd POA/POI and I'm done. Irons I use for those times I'm a dumbass and forget to turn the optic on or it goes dead.

DocGKR
04-12-07, 14:53
I zero my irons first.

Then I zero my optic.

When using my preferred red-dot optics (Aimpoints in LaRue mounts) in every case to date, the red-dot has been perfectly centered on the iron sight front post tip when looking through the irons and optic simultaneously. In other words, my irons and red-dot have the same POA/POI and are CO-WITNESSED.

If my red-dot and BIS have been co-witnessed during the initial zero, then at the beginning of each shift/operation I can flip-up the BIS and ensure the red dot is co-witnessed as a quick verification that my zero has not shifted. Then I flip-down the BIS and go about my business. In my world, that is the main benefit of co-witness.

SinnFéinM1911
04-13-07, 07:37
Co-witness = seeing two at the same time, regardless of plane.. equal to or bottom 1/3. The key point is being able to rapidly shift to irons in the unlikely event your optic fails.

An EoTech on a riser will put the irons below the red dot, many Aimpoint mounts do this by design. You then have to zero Irons & Red Dots seperately.

Many folks get lazy and just zero the dot & move the Irons to it.... or vice versa. The validity of this zero depends on the plane of the optic/dot and the irons. Best to zero one then the other seperately.

I have also heard as it as:

A ability to quickly sight in your Iron after your Optics / Red Dots BZO'd, and adjsut your iron sights or buis to that point (seems kinda lazy to me).

Robb Jensen
04-13-07, 07:40
I have also heard as it as:

A ability to quickly sight in your Iron after your Optics / Red Dots BZO'd, and adjsut your iron sights or buis to that point (seems kinda lazy to me).

Very lazy. I think they should be sighted in independently so you'll know each works on it's own.

Wayne Dobbs
04-13-07, 08:10
I think that however it's ultimately defined, co-witnessing does involve being able to see and use both systems at the same time.

As an alternative and to put a Pat Rogers spin on it, "...co-witnessing is watching TWO hot chicks get it on...."

militarymoron
04-13-07, 09:32
Argument to that is this:
Iron Sights and Red dots DO NOT print the same on a 25M zero target so if you adjust them separately @ 300m your will not have the same POA/POI. (This is why SOPMOD has offset Targets)


brett, do you have a pic of that SOPMOD target? is it specifically for the aimpoint, or another optic?

i always understood co-witnessing to mean that you can see the irons through the optic window, whether they be centered or in the lower third, and that when looking through the irons, the dot would be adjusted to coincide with that sight picture (sitting right on the front sight), or vice-versa, which would give you the same POA/POI as long as you look at the dot through the irons at any distance.

once you look at the dot ABOVE the irons, then the POI will be the same as the POA only at that zero distance (25M). at any other distance, there will be a slight divergence proportional to your eye's height above the iron sight line.

SinnFéinM1911
04-13-07, 11:52
I guess this is what I am saying. and I think everyone here has shown that there is NO true ONE definition to a "Textbook" or Doctrine to a actual Co-Witness. Its amazing to me that a term that is so widely used and thrown around as "must have" when buying optics and BUIS is a true unknown.

SinnFéinM1911
04-13-07, 11:55
brett, do you have a pic of that SOPMOD target? is it specifically for the aimpoint, or another optic?

i always understood co-witnessing to mean that you can see the irons through the optic window, whether they be centered or in the lower third, and that when looking through the irons, the dot would be adjusted to coincide with that sight picture (sitting right on the front sight), or vice-versa, which would give you the same POA/POI as long as you look at the dot through the irons at any distance.

once you look at the dot ABOVE the irons, then the POI will be the same as the POA only at that zero distance (25M). at any other distance, there will be a slight divergence proportional to your eye's height above the iron sight line.


I do have one (a few really), I send a PM and let you know, but ecentailly it had POA being center of the target and you adjsut the Kit to the POI as drawn on the tartget.

Snake RAH
04-13-07, 11:59
I'm confused. How is POA/POI different between irons and red dot optics? If zeroed for the same range, using same ammo, the difference between the two to me is nil...group size with the red dot is smaller than the irons, unless I'm shooting a rifle-length sighted gun.

SinnFéinM1911
04-13-07, 12:00
There are different offsets depending on Ammo types and Optics and Lasers.

combatvet
04-13-07, 12:11
In my Arm chair commando opinion:

The only right way to do this is to first sight in your BUIS(s) and then "co-witness" your dot/scope/whatever.

That way if you ever have an optic failure you know for certain your BUIS(s) are calibrated for POA.

militarymoron
04-13-07, 15:07
I'm confused. How is POA/POI different between irons and red dot optics? If zeroed for the same range, using same ammo, the difference between the two to me is nil...group size with the red dot is smaller than the irons, unless I'm shooting a rifle-length sighted gun.

it's not different - it's the same, at the distance both are sighted in, and as long as you're looing through the irons when sighting the dot. but if you move your head up and look over the irons, the POI will be different for ranges OTHER than what you sighted them both in.

SinnFéinM1911
04-13-07, 15:52
It will actually be different.

Example:
@ 25m If you have X sight, your POA will be center mass on the Target. However, you need to put your POI approx 1.23 inches to the 12 o'clock, for a proper 300m BZO of that sight or optic/red dot.

Harv
04-13-07, 16:31
Originally post by DocGKR


I zero my irons first.

Then I zero my optic.

When using my preferred red-dot optics (Aimpoints in LaRue mounts) in every case to date, the red-dot has been perfectly centered on the iron sight front post tip when looking through the irons and optic simultaneously. In other words, my irons and red-dot have the same POA/POI and are CO-WITNESSED.

If my red-dot and BIS have been co-witnessed during the initial zero, then at the beginning of each shift/operation I can flip-up the BIS and ensure the red dot is co-witnessed as a quick verification that my zero has not shifted. Then I flip-down the BIS and go about my business. In my world, that is the main benefit of co-witness.
This is the technique I was taught with Big Green and still use today.

It has worked for me for me as long as I have been using a Aimpoint.

If my Gun takes a hard hit on the deck... I pop up the BUIS and can verify my red Dot zero to My BUIS.

As to the whole 1/3rd Co witness vs. a "true" co-witness.....

Never got wrapped around the axle on that.

I like my Irons usable and within the Aimpoints field of view, but not dead center..

I think to many shooters get wrapped about where there Irons are within that field of view..

The way I look at it..If I'm outside of transition range and the dot fails, the Irons go up and I shoot them until I can get the dot sight back up.. if the dot sight "ain't" coming back up for a while, I'm swinging a throwlever and ditchin it(Stashing it to fix/replace at a later date) and going with all Irons. So true co-witness or 1/3rd co-witness is moot at that point.

I guess for me the Aimpoint is like my regular brake and the BUIS's are like my Parking brake, as long as it's in a familiar location, and I test it from time to time to see if it works... I'm good to go...I don't really give it much more thought then that....

militarymoron
04-13-07, 17:17
It will actually be different.

Example:
@ 25m If you have X sight, your POA will be center mass on the Target. However, you need to put your POI approx 1.23 inches to the 12 o'clock, for a proper 300m BZO of that sight or optic/red dot.

we're saying the same thing in two different ways. but the difference is in the details.
i think there's some confusion - using the dot when looking THROUGH the irons and using the dot when looking OVER the irons. when looking through, POA/POI is the same, when looking over, it's different.
i believe your example above is when using the dot OVER the irons, not looking through them.

SuicideHz
04-13-07, 17:36
Ok, I only read half...

Putting my Eotech on the LaRue 110 I can still get a co-witness.

Removing the LaRue and mounting the Eotech on my flattop gives me an ABSOLUTE co-witness where the dot is just about at the tip of the irons.

Right?

Snake RAH
04-13-07, 17:48
MM and SF1911,

I guess I have some more shooting to do. I know that I don't shoot my optic while looking through the irons, since I haven't taught myself to use all that sighting stuff. It's one or the other, but not both at the same time.

In the end, when the optic and irons are both zeroed to the same range, I find that if I do look through the irons, the optic (for me, usually the EOTech) reticle is on top of the irons.

militarymoron
04-13-07, 18:16
if you're looking through the irons, the eotech dot can be adjusted so that it's on top of the front sight whether or not it's in a LaRue mount or right on the flat top, assuming you've adjusted the dot and irons to each other.

i just chatted with brett on the phone - we're on the same page.

here's my .02 on the terms:
co-witness: to me, this just means that i'll be able to look through my irons anywhere in the optic window or tube, and be able to adjust the irons without removing the optic. the dot may or may not be adjusted to sit right on top of the front sight when you're looking through the irons. for example, you may have your irons adjusted for POA/POI at 25M and your dot at 100M. when you look through the irons, the dot will NOT be sitting on the front sight. they're zero'd for different ranges. in simple terms (to me) 'co-witness' means 'i can see my irons through my optic', regardless of how they're zero'd.

absolute co-witness: i think some have accepted this to mean that the irons are centered in height in the tube/window. i don't think it matters - that's just how much of the irons you want in your sight picture when you're looking through the optic. what it means to me is that regardless of whether the irons are in the lower third or centered in the optic, you've adjusted either the dot or irons to COINCIDE when looking through the irons. that way you can check them against each other. so, (to me), 'absolute co-witness' mean the dot is right on top of the front sight WHEN I LOOK THROUGH THE IRONS.

here's where the details (and confusion) comes in. if you've co-witnessed the sights, POA/POI will be the same WHEN YOU LOOK THROUGH THE IRONS. if you normally use the dot sight by looking OVER THE IRONS (as in a lower third co-witness), the POA/POI will be the SAME only at that distance the sights were zero'd at (let's say 25M). at all other distances, they will diverge. this is because when you look over the irons, with your eye half an inch above the line of sight through the irons, you've now introduced an offset to the dot +(as it 'follows' your eye, being parallex free), and created a new line of sight that is not parallel to the iron line of sight. both lines of sight will cross where you've zero'd them at, but only at that one distance, which is why your POI will be different from POA for the irons and dot when looking OVER the irons. not sure if that makes sense.

militarymoron
04-13-07, 18:20
MM and SF1911,
In the end, when the optic and irons are both zeroed to the same range, I find that if I do look through the irons, the optic (for me, usually the EOTech) reticle is on top of the irons.

yes, agreed, as they should be when 'absolute co-witnessed' (which has nothing to do with center/lower third position).

SuicideHz
04-13-07, 19:04
So what you are saying MM is that if the dot isn't sitting on top of your irons then it's still absolute cowitnessing if you can move your dot so that it sits on top of the irons?

For instance, on my Eotech on LT110, the dot can be moved basically anywhere in the window. I have a KAC 300m flip rear so it's almost always down. I CAN if I want, adjust my view so the dot sits on top of my front iron, but that's not an absolute cowitness because I would think that to absolute cowitness the dot would have to sit on the front sight when the front and rear are lined up correctly.

militarymoron
04-13-07, 19:52
suicide, not sure if i understood what you meant. the dot is only 'absolute co-witnessed' if it's sitting on the front sight WHEN you're looking through the irons (front lined up with rear). if your rear sight is down, and you move your head so the dot is on top of the front, you're just lining up your eye to where it'd be when looking through the rear sight if it were flipped up and you had them lined up.
when you're not looking THROUGH the irons, the dot can be anywhere in the window - its position relative to the front sight is irrelevant - top, to the side, lower etc. so, in other words, when your rear sight is flipped down and you're using the dot, ignore the front sight and don't bother trying to put the dot on it.

Redhat
04-13-07, 20:22
Do the procedures in the Army FM work?

SuicideHz
04-13-07, 22:19
MM- yes, that's exactly what I was getting at. It's just that when I gave my interpretation and I first mentioned "absolute" I thought you were making a point to state something else and not just corroborate.

Absolute is when the rear is flipped up that the irons AND dot align (somewhat.)

I can have my irons zeroed perfectly at 50 and my Eotech zeroed perfectly at 50 but when I use them together the dot isn't perfectly on top of the front. I think that's just a little error introduced by each and how they are used that was touched on earlier by someone.

For instance, If I take my 512 off of the mount and put it on the flattop and flip up the KAC, the dot is off to the left on top of the front post. I think that's due to the Eotech's clamping system on the rail but then again, it should be centered...

I'm rambling. It's friday and I just came from the bar...

;)

mark5pt56
04-14-07, 08:33
My understanding is that a "true" cowitness is the irons and dot being aligned together as viewed though a iron sight picture. I've never seen the point in that, defeats the advantages of the dot.

I've heard the argument, that if the dot fails, you don't have to shift your head.

I have mine with a Larue mount, so the irons are on the bottom third, dot unobstructed.

I've never seen a dot hit the same poi with the same poa as the irons when the dot is set on top of the front sight as viewed through the rear.

Redhat
04-14-07, 09:39
Some good points.

But the dot, if zeroed for 300m using 25m target, should be adjusted POI 1.5cm below the targets aiming point. Lolly popping the dot to the top of the front sight post only puts you on paper. Assuming you are using the M68 with issued mount and M855.

That's what I've heard anyway.

militarymoron
04-14-07, 10:59
the utility of a 'absolute/true' co-witness, IMHO, is as a sanity check to see if anything has shifted, or checking that you optic is still zeroed when you remove and replace it. the dot doesn't have to be co-zero'd with the irons to do that - you can zero the dot independantly, then check to see where it is in relation to the front sight when looking through the irons (windage should be centered, but you can be 'one dot width' above the FSP, etc).

normally, you'd never look through the irons when using the dot. i agree - it defeats the purpose. however, there have been instances where i HAVE utilized the rear aperture with the dot to sharpen it up. the sharpness of the dot depends mostly on your vision. my eyesight isn't that good, and using the small rear aperture when sighting in the dot, or for longer ranges on small targets acts like almost like a pinhole camera and sharpens up a dot that might appear a bit blur or fuzzy. for those with less than perfect vision, look at your dot, then flip up the rear sight with the small apreture and look through it again. chances are you'll see a sharper, more distinct dot.

i think the point of brett's original post was to try to get some agreement/standardization on the terms used. here are my suggestions for defining the terms:
Co-witness - the ability to view the irons sights through the tube. This applies to any height of the optic relative to the irons, as long as they can be seen. the dot can be adjusted to the irons or zero'd independantly.
Co-zero'd - i suggest discarding the terms 'absolute' or 'true' co-witness as they're confusing. this is when the dot is adjusted so it sits on top of the FSP when looking through the irons. the zero will only be valid for the distance they're both zero'd at.

C4IGrant
04-14-07, 11:02
I zero my irons first.

Then I zero my optic.

When using my preferred red-dot optics (Aimpoints in LaRue mounts) in every case to date, the red-dot has been perfectly centered on the iron sight front post tip when looking through the irons and optic simultaneously. In other words, my irons and red-dot have the same POA/POI and are CO-WITNESSED.

If my red-dot and BIS have been co-witnessed during the initial zero, then at the beginning of each shift/operation I can flip-up the BIS and ensure the red dot is co-witnessed as a quick verification that my zero has not shifted. Then I flip-down the BIS and go about my business. In my world, that is the main benefit of co-witness.

This is how I do it as well.


There seems to be a lot of debate as to whether an "absolute" co-witness (as Dick S. used to call it) is the preferred version of the co-witness.

Most of us I think prefer a bottom 1/3 co-witness simply for the reason that it keeps more of your irons out of your FOV. I think people sometimes forget that the optic is the PRIMARY sighting system and the irons are the secondary.

To make it even more interesting, I have even seen some Tier 1 weapons that did NOT co-witness at all (on purpose). The thought was that an optic that is mounted up higher allows for ones head to be more upright giving better Situational Awareness. If the optic goes down, the operator can still point shoot until he can remove the optic and go to the irons.

I have been practicing this recently, by removing my optic and just using my front sight base (no rear) to shoot human size targets out to 75yds! It is VERY easy to do and am fairly confident that I could keep someones head down at much longer distances.


C4

DrMark
04-14-07, 16:06
...so after this thread, I'm picturing a Vodka ad: Absolut Co-Witness

Too bad I have no Photoshop skills. ;)

2011BLDR
04-14-07, 16:54
An optic that is mounted up higher allows for ones head to be more upright giving superior performance in the following areas:
Better Situational Awareness
Less helmet shift that interferes with vision and sighting
Less neck strain from having the helmet and NVG’s tilted off center
Overall better balance and smother movement

Optics are the primary and in some unit’s the 2nd back up. If the primary is a 1.?-4X of some kind (TR21, Short Dot, NF…) the CQB dot (M68, EoTec, MRD) is the secondary and the Irons are the last resort . If the optic goes down, the operator can still shoot using the window, silhouette of the optic or a top adjustment knob as a reference point to aide in alignment until he can remove the optic and go to a secondary optic before being reduced to the irons.

The advantage of the optic is in reducing the number of things in the sight picture down to 2 ( retical & Target) from 3 ( Rear sight , Front sight & target). The “absolute co witness “ is a step back wards as you now have 4 things in the sight picture (Rear sight , Front sight retical & target).

Out,
2011BLDR

Mojo58
04-14-07, 19:46
...so after this thread, I'm picturing a Vodka ad: Absolut Co-Witness

Too bad I have no Photoshop skills. ;)

:D LOL:o

SinnFéinM1911
04-16-07, 08:04
the utility of a 'absolute/true' co-witness, IMHO, is as a sanity check to see if anything has shifted, or checking that you optic is still zeroed when you remove and replace it. the dot doesn't have to be co-zero'd with the irons to do that - you can zero the dot independantly, then check to see where it is in relation to the front sight when looking through the irons (windage should be centered, but you can be 'one dot width' above the FSP, etc).

normally, you'd never look through the irons when using the dot. i agree - it defeats the purpose. however, there have been instances where i HAVE utilized the rear aperture with the dot to sharpen it up. the sharpness of the dot depends mostly on your vision. my eyesight isn't that good, and using the small rear aperture when sighting in the dot, or for longer ranges on small targets acts like almost like a pinhole camera and sharpens up a dot that might appear a bit blur or fuzzy. for those with less than perfect vision, look at your dot, then flip up the rear sight with the small apreture and look through it again. chances are you'll see a sharper, more distinct dot.

i think the point of brett's original post was to try to get some agreement/standardization on the terms used. here are my suggestions for defining the terms:
Co-witness - the ability to view the irons sights through the tube. This applies to any height of the optic relative to the irons, as long as they can be seen. the dot can be adjusted to the irons or zero'd independantly.
Co-zero'd - i suggest discarding the terms 'absolute' or 'true' co-witness as they're confusing. this is when the dot is adjusted so it sits on top of the FSP when looking through the irons. the zero will only be valid for the distance they're both zero'd at.

I sat back and thought about this over the weekend over many, many pints of Guinness and using the term "Co-Zero", if your BUIS or Sight already sit in thee bottom 1/3 of your Optic / Red Dot, and your BZO your Optic /Red Dot @ 25m, and then adjust your Sights to it, your will not have a correct 300m BZO. Or even the other way around.

Lets just say that you sight in your Optic / Red Dot @ 25m and then adjust your Irons to them. Well then look at the setting on your elevation, it will be way blown out due to the fact that you (from the start with your lower 1/3 co-witness) have a gross adjustment of coming up at .25" or more. Then after your Rear is at the correct level, bringing your front sight post up to Co-Zero would be almost to the point of your Front Sight Post and Detent coming out or damn close to it.

IF your sights are on the same level with a Co-Axis with the plan of each being the same plan, it would be close or if not perfect for the idea of Co-Zero to work.


And going back to another question that was brought up earlier (sorry for hi-jacking my own thread). There is DIFFERENT POA/POI for different Optics / Red Dots with many variables in place, ammo types, optics, bbl lengths, etc. Example: Say you sight a EOTech in @ 25m (and the offset is 1.25 low) and your think that your POA/POI in Center mass of the Black Dot or Circle and your zero it to that. Then push your 25m BZO to 300m and see what happens. IF you were at center mass on that @ 300m your will be aprox. 15” High, and that is in perfect conditions taking out all accountable errors, IE MOA of ammo and the aprox 1 MOA for shooter added to the MOA of the gun. In all reality your could be pushing to a extreme of almost 30” off your center mass BZO @ 25m. Hope that makes sense !


B

rob_s
04-16-07, 09:23
Wow, I have to say I'm amazed that this discussion has actually gone on for three pages. I never would have thought this would have ganered even 1/20th of the attention.

SinnFéinM1911
04-16-07, 09:38
Wow, I have to say I'm amazed that this discussion has actually gone on for three pages. I never would have thought this would have ganered even 1/20th of the attention.

ARE YOU SAYING MY TOPICS ARE DUMB ! :confused:

jk

rob_s
04-16-07, 10:34
ARE YOU SAYING MY TOPICS ARE DUMB ! :confused:

jk

no, but....;)

I think that everyone is going to have their own way of doing things, and as long as what they're doing works for them and they made an informed decision about their way then it's all good. I understand the need to all be on the same page, but topics like this have a tendency to become nothing more than semantics.

I just got done with a three day carbine class where I shot a 3x mini-ACOG for two days and an ML2 for the last day. Co-Witness wasn't even an option for me on the first two days.:D

SinnFéinM1911
04-16-07, 10:50
no, but....;)

I think that everyone is going to have their own way of doing things, and as long as what they're doing works for them and they made an informed decision about their way then it's all good. I understand the need to all be on the same page, but topics like this have a tendency to become nothing more than semantics.

I just got done with a three day carbine class where I shot a 3x mini-ACOG for two days and an ML2 for the last day. Co-Witness wasn't even an option for me on the first two days.:D

Well, it is kinda of hard to view any kind of Sights or BUIS though any magnifed optics :D .

I was pretty much just trying ot make a point that people refer to it many times in reference to "WHY" they purchuse sights or certain mounts for Optices or Red Dots, when most of the they dont really know what they are looking for.

And ot mutulply the problem IF you force a Co-Witness with all you WILL NOT have a correct 200 or 300 m BZO.

rob_s
04-16-07, 11:11
I was pretty much just trying ot make a point that people refer to it many times in reference to "WHY" they purchuse sights or certain mounts for Optices or Red Dots, when most of the they dont really know what they are looking for.
Very good point, and really it carries over into the whole entire idustry. This is the thing that keeps TOS going, in fact.;)


And ot mutulply the problem IF you force a Co-Witness with all you WILL NOT have a correct 200 or 300 m BZO.

This is why I prefer to zero both seperately and see where everything winds up.

militarymoron
04-16-07, 14:41
Lets just say that you sight in your Optic / Red Dot @ 25m and then adjust your Irons to them. Well then look at the setting on your elevation, it will be way blown out due to the fact that you (from the start with your lower 1/3 co-witness) have a gross adjustment of coming up at .25" or more. Then after your Rear is at the correct level, bringing your front sight post up to Co-Zero would be almost to the point of your Front Sight Post and Detent coming out or damn close to it.
B

LOL - sometimes semantics are fun to discuss, too. actually, discussing semantics assumes that your already have a basic understanding of the discussion and are digging for deeper understanding and definition. on TOS, it's just 'what's co-witnessing?' instead of delving into the nuances. i find this discussion refreshing as i can learn more, and maybe identify my own misconceptions.
but since brett asked the original question, i do see merit in having the terms clearly defined/standardized, especially when it comes to military RFPs/contracts etc. and hey, what else would i do on my lunch break? :D

brett, in the above situation, the elevation of the irons won't be 'blown-out', because you're not trying to bring up the irons to the height of the center of the optic, just adjusting the irons so they coincide with the dot when looking through them. the dot is parallex free, so it 'moves' down in the vertical plane to the level of the irons when you look at them. if someone wants the optic irons centered in the optic (like if they wanted to use the front sight and optic tube as a large ghost ring as someone else mentioned above), they'd just get a lower mount.

SinnFéinM1911
04-16-07, 15:12
If you have a elevation drum on your rear, your would have to be almost at 500m to reach the red dot center, so it could not be a true 300 m BZO.

What if your engagment is at say 550m, how would you adjust ?

militarymoron
04-16-07, 15:36
brett, guess i'm not understanding why you'd adjust the iron sights any different than normal since you're not trying to put them in the center of the tube. if you sight in the dot at 25M, and the irons at 25M, when you look through the irons, the dot will be very close to being on top of the front sight, even with a lower third co-witness.

SinnFéinM1911
04-16-07, 15:56
brett, guess i'm not understanding why you'd adjust the iron sights any different than normal since you're not trying to put them in the center of the tube. if you sight in the dot at 25M, and the irons at 25M, when you look through the irons, the dot will be very close to being on top of the front sight, even with a lower third co-witness.

If someone is looking for the "Co-Zero" meaning Irons aligned with Optics / Red Dots, and they sight there Optics / Red Dot and then try to adjust thier Irons to the Optics / Red Dot (and they use a lower 1/3 co-witness) they will have a min. of 1/4 inch just to start. A inch in Sight Elevation is ALOT to be moving a Rear Sight to have "Co-Zero". Did I clear it up ?

2011BLDR
04-16-07, 16:39
What I have used and taught for the last 20+ years for the 5.56MM system on Active Duty, as separate stand alone evolutions:

- Iron sights BZO @ 1000” ( 27YD /25M) this will match up 200M with a 20” barrel and 300M with a 14.5”
- Verify and fine tune Iron sights BZO @ 200M or 300M as applicable for barrel length
- Verify Iron sight POI vs. POA at the following distances 3M 10M 15M 25M 30M 40M 50M 75M 100M 125M 150M 175M 200 M225M 250M 275M 300M and any additional distances that ranges will support, shooter learns hold under and over as applicable to the ranges.
- CQB Optics BZO @ 50M
-Verify CQB Optics POI vs. POA at the following distances 3M 10M 15M 25M 30M 40M 50M 75M 100M 125M 150M 175M 200M 225M 250M 275M 300M and any additional distances that ranges will support, shooter learns hold under and over as applicable to the ranges.
- Magnified optics BZO @ 50M for things without a BDC ( TR21, CQT….) 100M for BDC equipped optics ( Short Dot, ACOG…..)
-Verify Magnified Optics ( without a BDC ) POI vs. POA at the following distances 3M 10M 15M 25M 30M 40M 50M 75M 100M 125M 150M 175M 200M 225M 250M 275M 300M and any additional distances that ranges will support, shooter learns hold under ,over and exact long distance match up range as applicable.
-Verify Magnified Optics ( with a BDC ) POI vs. POA against the BDC at the following distances 3M 10M 15M 25M 30M 40M 50M 75M 100M 125M 150M 175M 200M 225M 250M 275M 300M and any additional distances that ranges will support, shooter learns exact margin of error in the BDC for them selves and the hold over under for the ranges closer than 100M as applicable.



I consider the "absolute co-witness” as Co-Alignment and the bottom 1/3 as Co-Witness.

Whenever possible I try to talk anyone out of using either and using the higher mounted optic to support a heads up shooting position and lower profile fold down iron sights for the reason I posted before.
Out,
2011BLDR

Chris_C
04-16-07, 22:47
I never understoof how people think "Just move the dot until its on top of your front sight post.." is "good enough".

If you zero one, zero the other. They they dont line up, something is wrong.

M193 BALL
04-17-07, 17:04
Choice A is the definition I use.

I do the zeroing backwards from you guys. I zero with irons, then put the dot on top of the front sight post, almost like a boresight. I then shoot just optics to verify or set the optic to shoot same POA/POI as the irons.





THATS WHAT I DID back in 2001

I think its a great way

Zero IRONS @ 50 yards

Put ML2 dot on the FSB Post

Then zero from there :)

wich only takes a few shots

also did my 551 that way




Works Great at my Local range since it only goes 200 yards another 20 yards to the Berm

Chuck & Forest help me out alot back then

M193 BALL
04-17-07, 17:06
I never understoof how people think "Just move the dot until its on top of your front sight post.." is "good enough".

If you zero one, zero the other. They they dont line up, something is wrong.




It will work

But I Fine tune a Click here and there

M193 BALL
04-17-07, 17:09
What I have used and taught for the last 20+ years for the 5.56MM system on Active Duty, as separate stand alone evolutions:

- Iron sights BZO @ 1000” ( 27YD /25M) this will match up 200M with a 20” barrel and 300M with a 14.5”
- Verify and fine tune Iron sights BZO @ 200M or 300M as applicable for barrel length
- Verify Iron sight POI vs. POA at the following distances 3M 10M 15M 25M 30M 40M 50M 75M 100M 125M 150M 175M 200 M225M 250M 275M 300M and any additional distances that ranges will support, shooter learns hold under and over as applicable to the ranges.
- CQB Optics BZO @ 50M
-Verify CQB Optics POI vs. POA at the following distances 3M 10M 15M 25M 30M 40M 50M 75M 100M 125M 150M 175M 200M 225M 250M 275M 300M and any additional distances that ranges will support, shooter learns hold under and over as applicable to the ranges.
- Magnified optics BZO @ 50M for things without a BDC ( TR21, CQT….) 100M for BDC equipped optics ( Short Dot, ACOG…..)
-Verify Magnified Optics ( without a BDC ) POI vs. POA at the following distances 3M 10M 15M 25M 30M 40M 50M 75M 100M 125M 150M 175M 200M 225M 250M 275M 300M and any additional distances that ranges will support, shooter learns hold under ,over and exact long distance match up range as applicable.
-Verify Magnified Optics ( with a BDC ) POI vs. POA against the BDC at the following distances 3M 10M 15M 25M 30M 40M 50M 75M 100M 125M 150M 175M 200M 225M 250M 275M 300M and any additional distances that ranges will support, shooter learns exact margin of error in the BDC for them selves and the hold over under for the ranges closer than 100M as applicable.



I consider the "absolute co-witness” as Co-Alignment and the bottom 1/3 as Co-Witness.

Whenever possible I try to talk anyone out of using either and using the higher mounted optic to support a heads up shooting position and lower profile fold down iron sights for the reason I posted before.
Out,
2011BLDR



100M difference from M4 to 20 ?? thats odd

I zero at 50 yards and getPOI around 220 with BUIS on M4 14.5 and ML2 and 551 on the other LMT

SS109/M855 and 77gr seem to have close to the same POI in my M4`s

mattjmcd
12-11-07, 15:00
For the guys who run an optic with the reticle above the irons, I have the following question-

Do you use a different zero for the optic? I am not sure if this makes sense, or if it's even a factor, but I wonder if it can be done? I currently run an EOTech with an absolute cowitness, and the irons are set to the battlesight zero advocated by TriCon/JG in his book. So the zero is the same for both.

If you placed the optic higher, using the lower-third view so often described here, could you set the optic's zero for a longer range zero? If you COULD do it, WOULD you? Does this even make sense as a question?

Thanks.

KevinB
12-11-07, 15:43
You could.

However if you run the irons in the lower 1/3rd if you drop your head intothe irons -- the dot will co-witness provided you use the same zero.

Robb Jensen
12-11-07, 16:01
With Aimpoints I zero the irons and then zero the optic. The optic on the rifle can be shot by looking over the irons and putting the reticle where you want the bullet to go (faster) or going lower on the stock and lining it up in the lower 1/3 (slower).

I like it higher because it's faster.

Some competition guys (like Daniel Horner and Ernest Langdon) run the very tall LaRue SPR scope mounts with S&B Short Dot scopes (the ones for mounting behind PEQ-2s) because they're a little faster than the standard 1.5s or SPR-Es because you don't have to get as low on the stock.

Tim_W
12-20-07, 18:28
I am building a 12" SBR. I am having trouble deciding on fixed or flip up BUIS for Co witnessing in the lower 1/3 of the sight picture. The optic will be a EO-Tech 553 or M3 with 4 moa dot. I have just read Pat Rogers latest article on red dot optics their proper uses in the Gun Rag and it has put me on the fence on this. I understand the negatives of having fixed centered Co witness site that was already out. What would you consider the best choice of the two, fixed 1/3 co witness or flip up centered or 1/3 co witnessed.

If going fixed it would be a LaRue rear BUIS with a standard pinned FSB or for the flips a set of Troy flip BUIS. This will be for a CQB and defensive gun, also the one I will use in classes such as Pats. It will be run hard by your definition Pat. It will be dirty far more than it will ever be clean. It will only be used with a zero magnification optic such as the two listed.

Which would give me the the best results in reliability and performance? Have any found a decrease in acquisition performance and speed with the fixed lower 1/3 co wit sites because of partial loss of that part of the site picture?

Do you know if the LaRue BUIS and FSB will Co wit to the lower 1/3 on the Aim point and the EO-Tech? Can they be made to with the proper LaRue mount? If so which. If it matters the hand guard will be a DD 9.5" FSB to a LaRue Upper.

Pat if you could weight in on this also I would appreciate your insight. By the way I tried to send you and IM on this question and it kicked it back because you're box is over full just an FYI.

Thank you in advance for taking the time to help.

Tim

ETA: I have tried sights both ways and they both seem to work well for me. I would give the edge to the fixed in transition speed. But I just don't know if others have found any deficiencies for having them fixed in the sight picture even if in the lower 1/3.

Robb Jensen
12-20-07, 18:55
The rear sight height is the same regardless of which BUIS you have. The co-witness height is regulated by the optic and or mount. A 553 will co-witness in the lower 1/3. A 552 will if you use a LaRue EOTech mount.

Tim_W
12-20-07, 19:00
What about the M3? Any preference to which you prefer fixed or flip in your goto gun.

Tim

Robb Jensen
12-20-07, 19:14
What about the M3? Any preference to which you prefer fixed or flip in your goto gun.

Tim

Personally I prefer fixed rear sights like the LaRue or LMT. For a lower 1/3 co-witness for an M3 either get the LaRue LT150 mount a ADM AD-68H.

Tim_W
12-20-07, 19:34
Thank you for the information. I am leaning towards the fixed at this point. Moving parts I think are just one more thing that can/will break or stop working when its needed.

Tim

11B101ABN
12-21-07, 02:15
It was drilled into my exceedingly thick skull to have your flip-up BUIS deployed when engaging anyway, so I got rid of it and got the LMt fixed rear.

Never looked back. Your rear sight should be available for immediate use, always.

Blake
12-21-07, 20:27
Tim_W,

This is a very user specific type of question. If you are able try both out extensively then make a choice. If you like both, then either make a choice or switch. I don't think anyone here can make a decision on something you need to make for your purposes. With that being said, you mentioned that it would be used in a defensive situation. Home Defense? Are you LE or MIL? You also stated that you would shoot it a lot. Is this for work or pleasure. The point is if you are going to shoot it a lot for training, and you would somehow manage to break of a flip up rear, you are immediately aware of it, you can fix it or replace it. If you are using it operationally then that is another story, breaking it would be of a big concern. If you are using it in home defense you're chances of breaking it are less of a concern. Not impossible. Neither choice is wrong, just a preference. Think about your needs in the most realistic sense.

Chessbay
04-10-08, 20:03
So, I just got my Troy flip up BUIS in the mail today.

I have a cheap BSA Red Dot Scope mounted on my weapon right now as well.

Unfortunatley, I can't kick out for a better optic right now so I would like to make do with what I have for now if possible.

As it's mounted my optic is too low to have a true cowitness. The BUIS are almost looking over the top of the optic. They are at least in the upper third of the optic.

Is there a scope mount that I can use to fix this? Some type of shim?

Or am I SOL until I purchase a new optic.



Thanks for the help.

Chessbay
04-10-08, 21:05
I've also noticed that my gas block sits about 1/4" lower than the flattop. This seems like it could create problems. Maybe not????

Man, I hate being completley new to something. I guess that's what site's like this are for.

Also, please correct me if I use the wrong terminology.


I've taken some pictures I'll try and post in the am.

Shihan
04-10-08, 21:06
You would have to use a riser of some type. If you are planning on getting another optic in the near future I would just leave it as is and not waste the money.

Oscar 319
04-10-08, 21:25
The Troy BUIS is good to go. Sight it in and roll with it (or use what came on the gun) until you can afford an EO, Triji or Aimpoint on a decent mount. You may want a 1/3 co-witness, thats what all the cool kids are using these days. I still like my dot on top of my front sight post (true co-witness). No worries, no hurries. Sounds like you have the gun. Go out and shoot the hell out of it and master the iron sights while you are saving up for an optic.

Chessbay
04-11-08, 06:43
The Troy BUIS is good to go. Sight it in and roll with it (or use what came on the gun) until you can afford an EO, Triji or Aimpoint on a decent mount. You may want a 1/3 co-witness, thats what all the cool kids are using these days. I still like my dot on top of my front sight post (true co-witness). No worries, no hurries. Sounds like you have the gun. Go out and shoot the hell out of it and master the iron sights while you are saving up for an optic.



Your right......good advice.

Do I need to be concerned that the top of the rail on the gas block is about 1/4" lower than the flat top rail?

Will this have an effect on sighting the rifle in? Should they not be mounted at the same height?

BC520
04-11-08, 10:23
That should only matter if you have a folding or detachable front sight that is designed to be installed on the top of a FF Rail system. If you post what you have for a front sight that will probably make it easier to clear up if its a factor or not.

nickdrak
04-11-08, 10:34
If you have both front & rear Troy flip-up sights then the front should be mounted on the handguard rail (which should be level with your receivers flattop rail), and not the gas block if it is lower than the handguard rail. A pic would help clear things up.

Otherwise, (Midwest Industries) makes a flip-up front sight which is the proper height for being mounted on a gas block rail:
http://www.bravocompanyusa.com/Midwest-Industries-MCTAR-FFG-front-flip-p/mctar-ffg%20(front%20flip%20gasblk).htm

Chessbay
04-11-08, 10:58
Alright, I hope the pictures work.

Sorry for the poor quality, but when I resized them the quality went down.


So, as you can see from the pictures I don't have a picatinny rail on my handguard. I only have the rail on the gas block, which is not level with the rail on top of the reciever.

I'd rather not buy a new handguard if I don't have to. I'd prefer to save my money for a better optic. Plus I would prefer to not dump tons of money into this gun because it's inexpensive and my first.

So, can I purchase a new gas block with a higher rail? What's the best fix?

nickdrak
04-11-08, 12:52
I would see if you can send the Troy front sight back, and get the MI gas block front sight that I linked above. They will work perfectly together. And you will actually save some cash as the MI is about $30 less than the Troy front sight.

wild_wild_wes
05-24-08, 02:25
If you have a rifle with folding rear AND front BUIS, do you HAVE to use the tall LT adapter?

Robb Jensen
05-24-08, 05:58
If you have a rifle with folding rear AND front BUIS, do you HAVE to use the tall LT adapter?


You can go with either. 1/3 co-witness is my preferred method. That way the sights don't block as much.

FJB
05-24-08, 14:56
Wild,
If using a Micro T-1 on an M4 carbine variant (whether fixed or folding front sight) you'll want to use the the LT66X Tall Riser or ADM Micro Mount with either standard (CO) or 1/3 (SOCOM) Witness spacers. LaRue Tactical is now making a mount for the Micro T-1 that works for HK416s using HK Diopter sights. The new LT660HK Micro T-1 mount is a very nice set up for the HK416 platform. See picture compliments of EAG Tactical.

S/F

wild_wild_wes
05-24-08, 15:37
I like the look of that HK mount, FJB. The lightening holes look like a good idea, even though removing that much aluminum prolly only saves a fraction of an ounce. But I will take your advice and go with the regular tall mount.

nickdrak
05-24-08, 19:47
Even with flip up/down iron sights I prefer the lower 1/3 co-witness set-up as it gives you a bit of a more "Heads up" position and field of view when viewing through the optic, as opposed to the absolute co-witness which requires you to get a lower cheekweld when obtaining your sight picture through the optic. I suggest that you go with the standard "Tall" mount.

Lengradde
05-25-08, 01:37
Hah..lower 1/3rd cowitness is a chinweld for me.:o

wild_wild_wes
05-26-08, 16:28
I want to put mine (when I get one) on a Vltor VIS. I have a regular Aimpoint on there now, but for some psychological reason I can only tolerate the optic in the old place, right above the mag well. There are supposed to be advantages to putting reflex sights as far away from the eye as possible, which is certainly an option with a monolithic upper, but it just doesn't "look right" to me. Has anyone overcome tradition and mounted a T-1 all the way forward on the rail, near the muzzle?

jbsf3
05-27-08, 08:22
FJB- nice mount. It appears that the HK416 mount is right between the LaRue high mount and low mount in terms of height, is that correct? I assume the HK416 mount works on any standard flat top upper? I've got a LT tall mount for my T-1 on the way but really prefer a co-witness set up, looks like the HK416 might fit that bill? Thanks for your time.

FJB
05-28-08, 02:15
FJB- nice mount. It appears that the HK416 mount is right between the LaRue high mount and low mount in terms of height, is that correct? I assume the HK416 mount works on any standard flat top upper? I've got a LT tall mount for my T-1 on the way but really prefer a co-witness set up, looks like the HK416 might fit that bill? Thanks for your time.

jbsf3,
The LTHK416 Micro mount is .3" lower than the LT 66X Tall mount, so it won't cowitness with standard M4 Carbine iron sights. The LT66X Tall mount is a 1/3 cowitness, but it is not as bad as you are thinking.

S/F

jbsf3
05-28-08, 02:30
Copy, thanks FJB!

762mmFMJ
06-02-08, 00:43
Can someone please post a pic of the shooter's view through an Aimpoint T-1 Micro. Preferably mounted on a carbine with a fixed front sight base, with the T-1 set up with a lower 1/3rd co-witness. Thanks.

YukonGlocker
06-02-08, 00:46
I would love to see this also.

Yojimbo
06-02-08, 10:06
Here's the best pic I've seen of the T1 from a shooter's perspective.

It's by MFinger showing the LaRue 1/3 cowitness mount. The front sight is is a Troy flip-up but a standard fixed FSB will look the same through the optic.

http://i2.photobucket.com/albums/y44/mfingar/LaRue_Tactical/T1_cowitnesscopy.jpg

Victor
06-02-08, 10:31
Mark DOES take some of the finest pics in the industry! I can only wish my camera skills can come close! :( I find the LT 661 about perfect and also co-witnesses perfect with a PVS-14 as well along with a GG&G tall mount for the 14. Great mounting solution to say the least!

Vic

BigRed
06-02-08, 15:04
Micro T-1 on my shorty at work.

BUIS is folded down.

Palmguy
06-02-08, 17:27
A little late to the game but oh well...


T-1 on LT Mount on a 14.5" LMT carbine:

http://i134.photobucket.com/albums/q116/bridoyal/113_1171.jpg

Phazuka
06-03-08, 21:24
Here's the best pic I've seen of the T1 from a shooter's perspective.

It's by MFinger showing the LaRue 1/3 cowitness mount. The front sight is is a Troy flip-up but a standard fixed FSB will look the same through the optic.

http://i2.photobucket.com/albums/y44/mfingar/LaRue_Tactical/T1_cowitnesscopy.jpg

how come the larue base doesnt cowitness the T1 with the FSB?

RyanB
06-03-08, 21:33
Because most LaRue customers want the iron sights in the bottom of the optics field of view. Myself included. It clears up the sight picture.

Phazuka
06-04-08, 16:03
In regards to dot sights, eotechs, acogs...which is better? Do you want your dot sight to cowitness with the front BUIS or do you want the rear and front BUIS to be in the lower 1/3rd of the sight picture?

Jay Cunningham
06-04-08, 16:17
There is no "better".

Lower 1/3 or so-called "SOCOM" co-witness gives a bit better field of view, some might say is less "cluttered."

But many run absolute co-witness just fine, and some prefer it because it shoulders the same/uses same cheekweld as irons.

This is one of those preference areas.

Dave L.
06-04-08, 16:22
I don't mind a Co-witness when I have a flip up rear BUIS in the down position. When I use a LaRue BUIS, Aimpoint, Fixed FSB, I prefer the SOCOM (Lower 1/3)- for me I can pick up my dot/target faster with less clutter.

mmike87
06-04-08, 19:33
I prefer lower 1/3 - easy to transition to irons, yet less clutter when using optics. As with everything, you'll be best with what you train with.

Dualspringfields
07-04-08, 20:43
Newbie here and sry if this is a stupid question.

Can you co-wittness with a Aimpoint Comp C3 sight???? And if so what would I need to get to do this? What mount???


Thanks Casey.

CarlosDJackal
07-04-08, 21:25
I use this: (Larue LT-129 Cantilever mount (http://stores.homestead.com/Laruetactical/Detail.bok?no=37))

It allows for a 1/3 co-witness. Good luck!!

Dualspringfields
07-04-08, 21:29
Thanks.
Any other opinions? The 4 MOA dot or the 2 MOA dot?
And sry for not knowing. But what is 1/3 co-witness?


Thanks Casey.

wichaka
07-05-08, 09:22
I looked thru a co-witness set up, then thru a 1/3 lower set up, such as the LaRue mount mentioned above. I think you'll like the 1/3 better. You get a better field of view, with less clutter when looking thru the aimpoint.

C4IGrant
07-05-08, 16:26
Newbie here and sry if this is a stupid question.

Can you co-wittness with a Aimpoint Comp C3 sight???? And if so what would I need to get to do this? What mount???


Thanks Casey.


Not with the mount that comes with it. You can if you buy a better mount.

We offer member pricing on Aimpoints and have the C3 in stock. Drop us a line if interested.


C4

C4IGrant
07-05-08, 16:27
Thanks.
Any other opinions? The 4 MOA dot or the 2 MOA dot?
And sry for not knowing. But what is 1/3 co-witness?


Thanks Casey.

Get 2MOA. Lower 1/3 means that your irons will appear in the lower 1/3 of the Aimpoint window.


C4

Dualspringfields
07-05-08, 17:14
Ok thanks

FJB
07-08-08, 02:06
Newbie here and sry if this is a stupid question.

Can you co-wittness with a Aimpoint Comp C3 sight???? And if so what would I need to get to do this? What mount???


Thanks Casey.

Go to www.downrange.tv/show2 "Aimpoint: The Red Dot Solution" to watch/learn more about Aimpoint sights and how to use them.

S/F

Dualspringfields
07-08-08, 05:53
Yep I did.

Thanks

John_Wayne777
07-08-08, 08:08
Thanks.
Any other opinions? The 4 MOA dot or the 2 MOA dot?
And sry for not knowing. But what is 1/3 co-witness?


It looks something like this:

http://i2.photobucket.com/albums/y16/jwayne_777/IMGP0736.jpg

The sights are in the lower 1/3 of the optic.

Dualspringfields
07-12-08, 23:17
Bought a CompC3 off a guy for $200.00. Used but very very little. No scratches or anything. Anyway thatnks guys for the help and all. Took it out today and sighted her at 50 yards. Didnt do too bad to me for someone who has never shot using one before. Using a stock trigger too. Got a new trigger coming. Going out again tomorrow.

Like I said thanks for the help fellas. Casey.

http://i119.photobucket.com/albums/o150/dualspringfields/DSC00805.jpg

http://i119.photobucket.com/albums/o150/dualspringfields/DSC00801.jpg
http://i119.photobucket.com/albums/o150/dualspringfields/DSC00800.jpg
http://i119.photobucket.com/albums/o150/dualspringfields/DSC00806.jpg

ballsout
07-18-08, 23:16
I think I understand how this 1/3 co-witness works with a sight but I still have not physically seen how this works. Will somebody explain the 1/3 and 100% co-witness, or even draw a small diagram?

Jay Cunningham
07-18-08, 23:20
An absolute co-witness means that when you look through your iron sights and optic your front sight post appears dead center in your optic with the red dot on the tip.

A lower third (sometimes called a SOCOM) co-witness does the same as above except in the lower third of the optic. You can slightly raise your head position and just view the dot.

Buckaroo
07-18-08, 23:33
To add just a bit of clarity (I hope).

If a "normal" height mount gives an absolute co-witness then you raise the optic just a smidgen to obtain a "1/3" co-witness.

ballsout
07-19-08, 02:04
An absolute co-witness means that when you look through your iron sights and optic your front sight post appears dead center in your optic with the red dot on the tip.

A lower third (sometimes called a SOCOM) co-witness does the same as above except in the lower third of the optic. You can slightly raise your head position and just view the dot.


So on absolute will the red dot be literally on the tip or resting on the tip?


and if i raise my head won't the dot go further down the front sight?

Jay Cunningham
07-19-08, 02:14
So on absolute will the red dot be literally on the tip or resting on the tip?


and if i raise my head won't the dot go further down the front sight?

An absolute means the sights align with the dot in the dead center of the optic. A lower third co-witness means the sights align with the dot in the lower third of the optic. The red dot will always sit on the tip of your front sight if you are looking through your rear. Remember that optics like the Aimpoint are parallax free, so as long as you can see the dot anywhere in the optic you are going to make your hits.

ballsout
07-19-08, 03:12
http://img521.imageshack.us/img521/9992/cowitnesslg7.th.jpg (http://img521.imageshack.us/my.php?image=cowitnesslg7.jpg)


Is this correct?

IF it is then is does the optic sit higher since the dot would be in the lower 1/3 of the optic?

Jay Cunningham
07-19-08, 03:38
http://i2.photobucket.com/albums/y44/mfingar/LaRue_Tactical/T1_cowitnesscopy.jpg

ballsout
07-19-08, 11:12
think i got it.

http://groups.msn.com/isapi/fetch.dll?action=MyPhotos_GetPubPhoto&PhotoID=nJwAAANwMUuAJ7JC8BIu3u5hfwsqH9Z0x3oIwsknAVfVqkoJ0B820UgDvJdctqwwGbFtqpVZEnbk

in what circumstances would one be better over the other. absolute vs 1/3

and last questions: Does that mean a 1/3 co witness optic will actually sit higher than absolute? Will a added spacer make your optic 1/3 OR is it for going from 1/3 to absolute?

LOKNLOD
07-19-08, 11:39
in what circumstances would one be better over the other. absolute vs 1/3


A lot of it is personal preference. I would say that 1/3 co-witness has all the advantages but none of the drawbacks. Your normal sight picture with the red dot will be less cluttered. On the other hand, I find it *slightly* more cluttered using the irons through the 1/3 co-witnessed optic, but not so much as to undo the value of having the red-dot more visible to me.


and last questions: Does that mean a 1/3 co witness optic will actually sit higher than absolute? Will a added spacer make your optic 1/3 OR is it for going from 1/3 to absolute?

Yes, the 1/3 co-witnessed optic will have to sit slightly higher. Some mounting systems do this by just being designed taller (Larue's mounts for example). Others, like the ARMS mount, use a spacer added into the body of the mount to change the height.

MX5
07-19-08, 16:19
Some people find the sight picture on their RDS "cluttered" and others don't. If you're heads-up with both eyes open, focused on the target or threat and superimpose the red dot, you get hits. Some of us find the sight is nothing more than a obscure blur. I don't even see it anymore unless I focus on the front sight. YMMV. Neither is right or wrong, but a matter of preference.

Jay Cunningham
07-20-08, 22:40
I decided to merge multiple threads discussing this concept and to tack this new combined thread since the question comes up so often.

:)

akula88
09-15-08, 06:17
There is no "better".

Lower 1/3 or so-called "SOCOM" co-witness gives a bit better field of view, some might say is less "cluttered."

But many run absolute co-witness just fine, and some prefer it because it shoulders the same/uses same cheekweld as irons.

This is one of those preference areas.

I now understood the FOV advantage, but I need clarifications on Point of Impact on 1/3 Co-Witness when zeroing the Red-Dot sight.

At 1/3 Co-Wit, practical wisdom says that (except at zeroed distance [example-50yards]); the point of impact between red dot and iron sight is slightly different. Further at distance beyond the 50-yards, accepted and 'published' ballistic trajectory would be off for the red dot sights, since it sits HIGHER compared with the iron sight plane. (Axis to bore ratio)

Is this concern valid or just purely hot gas??


I sat back and thought about this over the weekend over many, many pints of Guinness and using the term "Co-Zero", if your BUIS or Sight already sit in thee bottom 1/3 of your Optic / Red Dot, and your BZO your Optic /Red Dot @ 25m, and then adjust your Sights to it, your will not have a correct 300m BZO. Or even the other way around.

Lets just say that you sight in your Optic / Red Dot @ 25m and then adjust your Irons to them. Well then look at the setting on your elevation, it will be way blown out due to the fact that you (from the start with your lower 1/3 co-witness) have a gross adjustment of coming up at .25" or more. Then after your Rear is at the correct level, bringing your front sight post up to Co-Zero would be almost to the point of your Front Sight Post and Detent coming out or damn close to it.

IF your sights are on the same level with a Co-Axis with the plan of each being the same plan, it would be close or if not perfect for the idea of Co-Zero to work.

And going back to another question that was brought up earlier (sorry for hi-jacking my own thread). There is DIFFERENT POA/POI for different Optics / Red Dots with many variables in place, ammo types, optics, bbl lengths, etc. Example: Say you sight a EOTech in @ 25m (and the offset is 1.25 low) and your think that your POA/POI in Center mass of the Black Dot or Circle and your zero it to that. Then push your 25m BZO to 300m and see what happens. IF you were at center mass on that @ 300m your will be aprox. 15” High, and that is in perfect conditions taking out all accountable errors, IE MOA of ammo and the aprox 1 MOA for shooter added to the MOA of the gun. In all reality your could be pushing to a extreme of almost 30” off your center mass BZO @ 25m. Hope that makes sense !
B


My intention would be to shoot the red dot to as far as 200yards or slightly farther.

Please post your opinions...

Cameron
09-28-08, 17:46
I have two carbines set up with an EOtech:
one with the fixed front sight has a bottom 1/3 as I use a larue riser to keep the front sight out of the main portion of the EOTech window, the other has a flip up front so I don't need a riser and this gives a perfect co-witness in that the circle and the dot align exactly with the BUIS.
Neither of then cause a need to change POI/POA for the differing set ups as the difference is only a change in optic over bore of about 5/8" for the EoTech riser vs. EoTech sans riser... So I Zero at 50 yards with dots and irons all impacting the same.


http://i383.photobucket.com/albums/oo277/camz_pics/Guns/17%20inch/145and16inch.jpg

Outlander Systems
09-09-09, 22:19
Here's my equation, which may or may not resonate with you:

Backup iron sights:

Fixed - Go with a lower 1/3rd, you'll appreciate it.

Folding - Doesn't really make a difference, but lower 1/3rd can often be a bit taller than I'm naturally inclined to shoulder the weapon with. Absolute cowitness in this situation.

It's a matter of personal preference. I seem to work better with an absolute cowitness, but that's just me.

TheDarkOne
10-14-09, 11:31
I hate to keep beating this horse, but I would like a little more opinion as to which height optic people prefer and why.

I just got my lower 1/3 SOCOM riser from ADM, but am having second thoughts. What I hate is the new cheek weld, or "chin weld", required to shoot it. To me, keeping that cheek weld consistent aids to repeatability and accuracy. When you cheek that weapon system, it should feel the same every time. Thoughts?

Btw, I am running flip up irons and have them folded down.

C4IGrant
10-14-09, 11:36
I hate to keep beating this horse, but I would like a little more opinion as to which height optic people prefer and why.

I just got my lower 1/3 SOCOM riser from ADM, but am having second thoughts. What I hate is the new cheek weld, or "chin weld", required to shoot it. To me, keeping that cheek weld consistent aids to repeatability and accuracy. When you cheek that weapon system, it should feel the same every time. Thoughts?

Btw, I am running flip up irons and have them folded down.

I only run a lower 1/3. Why? Because I want as little of my FOV blocked as possible.

The more you head is "up" the better situational awareness you have.

Cheek weld does not matter when using a RDS (FYI). You can be upside down and hit your target as long as the dot is on it.

Sights should be up and ready to go. Too many times we see guys optics fail in training classes and then they are screwed as they have their sights down.


C4

rob_s
10-14-09, 11:39
I run lower 1/3 mounts entirely. I also prefer fixed front and rear irons, or irons flipped up if they have the capability. I run my guns with my nose on the charging handle and have no trouble finding the dot on either 30mm or micro Aimpoints.

When I have been forced to use an absolute cowitness mount I have felt like I was mashing my face into the stock, and I absolutely want at least a flip down rear sight (the front effectively ghosts away).

You might try a Knight's micro mount (http://www.knightarmco.com/shop2/index.php?productID=311) as IIRC it comes with two risers to give you either absolute or lower 1/3.

TheDarkOne
10-14-09, 11:47
I only run a lower 1/3. Why? Because I want as little of my FOV blocked as possible.

The more you head is "up" the better situational awareness you have.

Cheek weld does not matter when using a RDS (FYI). You can be upside down and hit your target as long as the dot is on it.

Sights should be up and ready to go. Too many times we see guys optics fail in training classes and then they are screwed as they have their sights down.
C4

I can see if you are running the irons up that lower 1/3 is optimal. (Btw, I bought my optic and riser from you, thanks for the good price ;) ). Realistically though, how often are these red dots going down? In the rare case that they do, I wouldn't say the shooter is screwed. You can still shoot through the tube, and those irons take less that 1 second to deploy.

I know cheek weld doesn't matter with aiming with and RDS, the bullet goes where the dot is, but I think it does matter with stability. Controlling recoil, shooting rapidly, transitioning between targets, etc. I think the more consistent and tighter things are, the better you shoot.

TheDarkOne
10-14-09, 11:53
I run lower 1/3 mounts entirely. I also prefer fixed front and rear irons, or irons flipped up if they have the capability. I run my guns with my nose on the charging handle and have no trouble finding the dot on either 30mm or micro Aimpoints.

When I have been forced to use an absolute cowitness mount I have felt like I was mashing my face into the stock, and I absolutely want at least a flip down rear sight (the front effectively ghosts away).

You might try a Knight's micro mount (http://www.knightarmco.com/shop2/index.php?productID=311) as IIRC it comes with two risers to give you either absolute or lower 1/3.

That smashed cheek feeling is what I like, or at least what I am used to. It just feels more stable to me. Plus it is the same weld as with irons.

I am using an ADM Mount which is modular as well, so I can change out risers if I want to. I am just trying to figure out which way to go before I spend the money. The new riser is only about $25 but I don't want to spend more unless I am sure.

C4IGrant
10-14-09, 11:55
I can see if you are running the irons up that lower 1/3 is optimal. (Btw, I bought my optic and riser from you, thanks for the good price ;) ). Realistically though, how often are these red dots going down? In the rare case that they do, I wouldn't say the shooter is screwed. You can still shoot through the tube, and those irons take less that 1 second to deploy.

I know cheek weld doesn't matter with aiming with and RDS, the bullet goes where the dot is, but I think it does matter with stability. Controlling recoil, shooting rapidly, transitioning between targets, etc. I think the more consistent and tighter things are, the better you shoot.


Optics are man devices and fail all the time.


Using the optics tube to shoot only works ok at best. When only hits count, why risk it??? How much training have you done with the tube only? How far was the target? How big was the target?

It takes longer than 1 second to deploy your optic and generally what happens is the shooter sits there for 10 seconds trying to figure out where their dot went.

No on stability, controlling recoil, shooting fast or engaging multiple targets. What DOES help with all of this is recoil management, muzzle flip control and trigger discipline. The bulk of these things are controlled by your weight balance, where your arms/hands are on the weapon and how you are applying force.


C4

Outlander Systems
10-14-09, 12:00
I can see if you are running the irons up that lower 1/3 is optimal...

A wise man once said, and I'm paraphrasing, "There's a reason they're called back UP iron sights"...

Just sayin'.

TheDarkOne
10-14-09, 12:04
Optics are man devices and fail all the time.

Using the optics tube to shoot only works ok at best. When only hits count, why risk it??? How much training have you done with the tube only? How far was the target? How big was the target?

It takes longer than 1 second to deploy your optic and generally what happens is the shooter sits there for 10 seconds trying to figure out where their dot went.

No on stability, controlling recoil, shooting fast or engaging multiple targets. What DOES help with all of this is recoil management, muzzle flip control and trigger discipline. The bulk of these things are controlled by your weight balance, where your arms/hands are on the weapon and how you are applying force.
C4

I am pretty new to shooting red dots, and have done 0 shooting out of the tube, but know it can be done. I figured it would be accurate enough to get you to a position to where you can flip your sights up though.

I guess my big complaint is the new cheek weld. I am not used to it, and it does not feel as stable. It may just be something I need to get used to.

TheDarkOne
10-14-09, 12:06
A wise man once said, and I'm paraphrasing, "There's a reason they're called back UP iron sights"...

Just sayin'.

So does everyone run their irons up with a red dot? Keep in mind, I am new to the game here, but from what I have seen, people seem to fold those down and out of the way.

C4IGrant
10-14-09, 12:08
I am pretty new to shooting red dots, and have done 0 shooting out of the tube, but know it can be done. I figured it would be accurate enough to get you to a position to where you can flip your sights up though.

I guess my big complaint is the new cheek weld. I am not used to it, and it does not feel as stable. It may just be something I need to get used to.

I am not new to shooting red dots, trying to use JUST the tube or training. :D

As I said only hits counts and of those, only quality hits make a difference.

The proof is in CQB shooting schools where the dot fails and the shooter just stands there trying to figure out WTF just happened. Then they realize that they need to be shooting the bad guy and miss (at close distances using "just the tube").

Training and practice is everything. Just like the guys that don't want to keep their other eye open when they shoot. It is just something you need to get over.

C4

C4IGrant
10-14-09, 12:10
So does everyone run their irons up with a red dot? Keep in mind, I am new to the game here, but from what I have seen, people seem to fold those down and out of the way.

Depends on how educated the shooter is. Meaning, has the person giving you feedback had any real training from a instructor worth a damn???

Both Vickers and Hackathorn teach to have your irons up and ready.



C4

TheDarkOne
10-14-09, 12:14
Depends on how educated the shooter is. Meaning, has the person giving you feedback had any real training from a instructor worth a damn???

Both Vickers and Hackathorn teach to have your irons up and ready.
C4

I don't want to get into a pissing match over instructors being worth a damn. I know that Costa and Haley run with their irons down. They seem pretty good to me. :)

C4IGrant
10-14-09, 12:27
I don't want to get into a pissing match over instructors being worth a damn. I know that Costa and Haley run with their irons down. They seem pretty good to me. :)

I have seen Costa with them up at a class. (FYI).

There is NO argument worth anything for keeping your irons down.



C4

rob_s
10-14-09, 12:48
So does everyone run their irons up with a red dot? Keep in mind, I am new to the game here, but from what I have seen, people seem to fold those down and out of the way.

I'm working on an article to explain this. If nobody pays me for it I'll wind up posting it here for free. ;)

"People" are stupid. Persons are smart. It's good that you are questioning what you see others doing. Think of how few of those people questioned anything, just assumed, and wound up making decisions based on what they saw others doing and/or based on zero time at the range.

I know this because I made this mistake myself. On my second AR I was absolutely convinced that I needed the irons to fold down out of the way of the optic, and I was wrong.

TheDarkOne
10-14-09, 12:52
I have seen Costa with them up at a class. (FYI).
There is NO argument worth anything for keeping your irons down.
C4

Well, the ONLY reason I can make is that you would have 1/3 more tube to look through. I am guessing this is not sufficient? ;)

Keep in mind, if I was to keep my irons up, there is no question whatsoever about what height riser to go with. SOCOM all the way!

Outlander Systems
10-14-09, 12:56
TheDarkOne:

Look at all the peripherals as tools in the box. For 1X sights, I'd prefer fixed BUIS. That's just me.

Folding BUIS, and anyone can feel free to correct me, really should only be down if you're using a magnified optic. This application requires you to, most likely, have the optic as far back on the receiver as possible due to eye relief. As well, in this situation, if you're possibly looking at "social" use of the weapon system, a QD mount for the magnified optic should be considered mandatory in the event of a failure.

Again, that's the only viable reason I could see to wield the weapon with the BUIS in the folded position.

Preference does have play, and I personally would prefer fixed irons on any weapon with a 1X sight.

Another side benefit of having your irons deployed constantly is a verification of an extreme loss of zero. Infrequent as this may be, it could provide a check for this, before it's "too late".

rob_s
10-14-09, 13:02
Be careful using a picture of a guy as an indicator of their position on something.

Some irons lend themselves to being down more than up for a variety of reasons, and those irons may be on a gun for unknown reasons. For example, the KAC 600 and 300 meter rears and the URX integrated from all are typically run in the down position and deployed as needed. So if one was shooting an SR15 or version thereof you might see them running with the irons down vs. up.

I don't know whether Travis and Chris run with them up or down and really don't care. I also wouldn't call someone inexperienced because they ran them one way or another. I would expect that just about everyone with any amount of training is going to try it both ways, find a way that they like and that works for them, and be able to articulate why they like their way if they feel they need to defend it.

TheDarkOne
10-14-09, 13:05
Does this discussion change at all if you are running MBUS.

Scenerio: You are running MBUS with a red dot absolute co-witness. The MBUS are folded down so you have optimal field of view. Red dot goes down, without removing your cheek from the stock you deploy the MBUS. The come up right in line with your eye, bang bang. I know you will disapprove but it seems like a pretty good set up to me.

C4IGrant
10-14-09, 13:07
Well, the ONLY reason I can make is that you would have 1/3 more tube to look through. I am guessing this is not sufficient? ;)

Keep in mind, if I was to keep my irons up, there is no question whatsoever about what height riser to go with. SOCOM all the way!

Nope.


C4

C4IGrant
10-14-09, 13:08
Does this discussion change at all if you are running MBUS.

Scenerio: You are running MBUS with a red dot absolute co-witness. The MBUS are folded down so you have optimal field of view. Red dot goes down, without removing your cheek from the stock you deploy the MBUS. The come up right in line with your eye, bang bang. I know you will disapprove but it seems like a pretty good set up to me.

No.


C4

TheDarkOne
10-14-09, 13:10
:) Well, it looks as though C4 is not budging.

TheDarkOne
10-14-09, 13:18
Be careful using a picture of a guy as an indicator of their position on something.


Yeah, and me using the Magpul guys as an example is baseless. Whether they fold them down or not, they both use the SOCOM height riser, which is what I am trying to decide on.

C4IGrant
10-14-09, 13:19
Be careful using a picture of a guy as an indicator of their position on something.

Some irons lend themselves to being down more than up for a variety of reasons, and those irons may be on a gun for unknown reasons. For example, the KAC 600 and 300 meter rears and the URX integrated from all are typically run in the down position and deployed as needed. So if one was shooting an SR15 or version thereof you might see them running with the irons down vs. up.

I don't know whether Travis and Chris run with them up or down and really don't care. I also wouldn't call someone inexperienced because they ran them one way or another. I would expect that just about everyone with any amount of training is going to try it both ways, find a way that they like and that works for them, and be able to articulate why they like their way if they feel they need to defend it.


It is kind of like your thread about "opinions are not always equal." Not all instructors are equal. Yes, they may make the same amount of money and some might even be more popular than others, but where the rubber hits the road is with their experience level.

When you get a VETTED Tier 1 guy telling you how it really is in combat (especially CQB), you better take notice of what they are saying!

Now will some people (or instructors) like their gear one way or another because it "feels" best to them? Sure. Is it anyone’s place to judge them for that? No. At some point though the thought that runs through my brain is if they have actually shot people with that setup or did they just make it up on the square range and decide it is "good to go" for combat?

Before we go down some horrible rabbit hole, can you learn stuff from instructors who have never been in combat (and killed people)? Sure can (I know I have). The most valuable info I have gotten though is from people that killed people for a living (and were successful at it). YMMV


C4

Thomas M-4
10-14-09, 13:20
I can see if you are running the irons up that lower 1/3 is optimal. (Btw, I bought my optic and riser from you, thanks for the good price ;) ). Realistically though, how often are these red dots going down? In the rare case that they do, I wouldn't say the shooter is screwed. You can still shoot through the tube, and those irons take less that 1 second to deploy.

I know cheek weld doesn't matter with aiming with and RDS, the bullet goes where the dot is, but I think it does matter with stability. Controlling recoil, shooting rapidly, transitioning between targets, etc. I think the more consistent and tighter things are, the better you shoot.

I used to run folding BUIS and swapped to a fixed BUIS lower 1/3 it works good for me. And I think running the Rear sight up is a must do red dots go down yes often no but did you ever think that if you had your red dot adjusted low for shooting in low light say in a room then you have to transition to shooting in the bright sun light?? The dot can get washed out by the sun then you have to readjust the brightness on your RDS. If you had the Irons up you could instantly take the shot and not be adj the brightness settings on your RDS.

Outlander Systems
10-14-09, 13:25
I keep hearing about a "clearer" sight picture with the BUIS down.

If you're shooting with both eyes open, this shouldn't be an issue whatsoever (ETA: if you have a proper cheek-weld, and are firing from conventional positions)

I've yet to see any benefit to having the BUIS down, whatsoever, short of my previously cited, and purely hypothetical example. This is also the reason, I prefer fixed over folding.

ROGOPGEAR
11-21-09, 01:38
It is kind of like your thread about "opinions are not always equal." Not all instructors are equal. Yes, they may make the same amount of money and some might even be more popular than others, but where the rubber hits the road is with their experience level.

When you get a VETTED Tier 1 guy telling you how it really is in combat (especially CQB), you better take notice of what they are saying!

Now will some people (or instructors) like their gear one way or another because it "feels" best to them? Sure. Is it anyone’s place to judge them for that? No. At some point though the thought that runs through my brain is if they have actually shot people with that setup or did they just make it up on the square range and decide it is "good to go" for combat?

Before we go down some horrible rabbit hole, can you learn stuff from instructors who have never been in combat (and killed people)? Sure can (I know I have). The most valuable info I have gotten though is from people that killed people for a living (and were successful at it). YMMV


C4

http://www.youtube.com/watch?v=9gYvW0nwkwM

Oh, but wait, that wasn't CQB, darn it. :rolleyes:

http://www.youtube.com/watch?v=MspNZJZb31g

Notice, iron (and polymer) sights down.


I think it's preference. ;)

C4IGrant
11-21-09, 09:07
http://www.youtube.com/watch?v=9gYvW0nwkwM

Oh, but wait, that wasn't CQB, darn it. :rolleyes:

http://www.youtube.com/watch?v=MspNZJZb31g

Notice, iron (and polymer) sights down.


I think it's preference. ;)


Having shot with Costa he does like his irons folded down. This is one of the FEW things that I would disagree with him on.


C4

TheDarkOne
11-23-09, 11:59
I keep hearing about a "clearer" sight picture with the BUIS down.

If you're shooting with both eyes open, this shouldn't be an issue whatsoever (ETA: if you have a proper cheek-weld, and are firing from conventional positions)

I've yet to see any benefit to having the BUIS down, whatsoever, short of my previously cited, and purely hypothetical example. This is also the reason, I prefer fixed over folding.

I agree, to really make the point, try putting the front cover on your red dot. You can shoot just as good despite having zero visibility out of your optic.


Having shot with Costa he does like his irons folded down. This is one of the FEW things that I would disagree with him on.
C4

I shoot irons up, but as fast as you can get those MBUS up, I really don't think it will make a difference in a combat situation. As long as he trains to do it, it will take him less than 2 seconds and wont even have to change his cheek weld.

CAInstructorTx
01-28-10, 08:59
I have seen shooters fire pinpoint groups with rifle X, and when I look through the glass, the dot is to the left and below of the front A frame. I've also seen it on the right, so I don't suppose it really matters. What I tell my students is zero the BUIS, then "lolli-pop" the red dot, flip the BUIS down, and commence zeroing the optic. It usually ends up all over the place for any given shooter, but as long as they're drilling it, then I'm not too concerned with where their red dot is as related to their irons, and I don't think they are either. It's all in what the user wants, and is comfortable with.

CAInstructorTx
01-28-10, 10:00
and on a side note, I've also taught the "front cover on-both eyes open" method, which makes co-witnessing a moot point. Either way, do what works. Different strokes for different folks, no real wrong way as I see it.

PlatoCATM
01-28-10, 18:02
That lollipop thing sounds great until you realize that some idiot instructor who didn't know what he was doing never told the squadron to forget about that lollipop when shooting. What you end up with is a group of 360 deployers who think proper sight alignment means trying to use two separate sighting systems together! Have fun un-****ing that group. It required my team obscuring the shooters' front sights entirely with some tape while they got used to shooting with just their RDS during the practice phase of fire at least. Every time I hear the word "lollipop" I cringe because I know that is the sight-alignment that shooter used last time when s/he failed to qualify.

CAInstructorTx
01-29-10, 09:32
the only reason I've seen the lollipop method used, and the only reason I use it, and only from time to time, is as a starting point. no bullets are ever fired with this setup, just basically to "mechanical zero the 68s" for the shooter prior to firing for zero. I have students who show up all the time with M4s that aren't assigned to them. That means that in a given year, the 68 has been re-zeroed for who know's how many different shooters before they picked it up. center the dot back up, "sorta" as it's kind of a pain to find the exact center of the optic on the line for the average shooter. So that's why I do it this way, no other reason. once the optic is re-centered/lollipopped, as far as my definition goes, the buis goes down, i tell the shooter to disregard the front sight, and center the dot in the optic, not on the front sight post. I've never had any problems doing it this way so far. I guess it all depends on the capacity of the shooter to take instructions, provided the proper instruction is given. I take care of my end of the deal, but obviously I can't vouch for every instructor out there. Very good and valid point Plato, good insight, and for the record, I have encountered those "****ed-up" individuals every now and then. I guess accountability is the basis of all military training.

Where are you at anyway Plato? Redhat or no? haha, trying to do that whole "networking thing" take care

Pathfinder Ops
01-29-10, 10:52
Personally I do not co-witness at all.

I zero my irons and my optic is mounted on an ARMS system that if it fails i just flip the lever drop it and roll irons till the work is done.

I can always see the front sight post through my optic but make no attempt to use them together.

I run a Leupold Mark 4 CQ/T ( http://tinyurl.com/57oeha ) so my optic does not require batteries to operate most of the time since the dot and ring are always present. The batteries only illuminate the dot & ring for low light if needed and frankly I rarely if ever have had to use them.

The only way my optic could fail is if actually destroyed/ broken glass. If that happens I pop the levers and it back to BUIS.

Maybe this is a wrong approach but it keeps things simple.

I do encourage folks to "cowitness" their optics in my training courses and help them figure out which works best for their set up/ shooting style and or needs.

hammonje
11-12-10, 09:36
Answer B. I like the absolute co-witness. I am not going to use the irons and the red dot together. I prefer the red dot to be mounted lower to the rifle.

I know others say you need it higher. Don't care....they have their multitiude of hypothetical and/or tactical experiences for such. I just put rounds on target more accurately with the optic mounted in line with the irons. I shoot a lot of irons and so I am used to this setup and my biomechanics are trained as such.

Run whatever suits your body and eyes.

Armati
11-20-10, 11:57
Body armor?

Who runs thier gun while wearing body armor?

It seems to me that most guys who do CQC shooting in body armor do not co-witness their optics at all. In general, the butt of the rifle sits on the plate over the pectoral muscle - not the shoulder notch. Guns come up and, dot in view, squeeze trigger.

Most guys want a taller riser mount. The new EOTechs put in an additional 1/4" rise.

In fact, I don't think you can really get a good cheek weld in body armor without craning your neck in a very unnatural position.

The new Daniel Defense/LAV gun seems to also have a very high riser on the T-1 which doesn't seem to co-witness at all.

Thoughts?

nickdrak
11-20-10, 14:49
The new Eotech EXPS integral QD riser mount gives the shooter a "Lower 1/3" co-witness, as does the Daniel Defense T1 riser mount. Both are typical "Lower 1/3" height.

duece71
02-15-11, 22:09
For a new person to RDS this discussion has been valuble. My head is spinning a little but I will go back and re-read some of the parts to understand even more. I just bought an Aimpoint with LaRue LT150 mount and it looks like the iron sights (FFSB and MI fixed rear sight) are visible in the lower 1/3 of the tube when the RDS is on. I have NOT sighted anything in yet (my range is closed Jan and Feb) so I have some time to do some more reading and research.
Thank you for all of the opinions and info.
P.S. Does eye relief for the RDS have any bearing on the 1/3 or absolute co witness discussion??? What is a good place to put the RDS to start???
Thank you.

sspro2340
03-26-11, 08:46
For a new person to RDS this discussion has been valuble. My head is spinning a little but I will go back and re-read some of the parts to understand even more. I just bought an Aimpoint with LaRue LT150 mount and it looks like the iron sights (FFSB and MI fixed rear sight) are visible in the lower 1/3 of the tube when the RDS is on. I have NOT sighted anything in yet (my range is closed Jan and Feb) so I have some time to do some more reading and research.
Thank you for all of the opinions and info.
P.S. Does eye relief for the RDS have any bearing on the 1/3 or absolute co witness discussion??? What is a good place to put the RDS to start???
Thank you.

by "put" for the rds are you referring to the actual unit, or do the dot itself? I am assuming you mean the rds...from my understanding and from the instruction i received you want to put the rds about in the middle of the gun say just before your delta ring/notch on your flattop
from what i remember this is done for control issues (keeping the weight of the optic centered on the system) and for "Tracking"

tracking the red dot: as you are looking at your target and bringing the optic to your eye to engage your peripheral vision will instantly see the red dot and you will be able to track it onto your target

its been awhile so if this isn't 100% sry, but no one else has answered u in a month or so, so i thought id give it a shot

tgace
03-26-11, 08:54
I always zero my irons then dial my dot to the front sight post tip to "put it in the neighborhood". Then I zero my dot.

sspro2340
03-26-11, 16:02
I thought I would throw up some pictures (since I'm more of a visual learner and this took me a while to get through my thick skull) to give folks a better idea on what the irons and rds looks like together and in terms of different sized mounts.

None of these pics are mine, I do not take credit for their work but appreciate every one of them, some are from users on calguns.net, another one of the pics is from ar15.com, and of course larue, or maybe another user from here, can't remember I apologize if one of these are yours and I did not mention you.

Here's a vid as well VID HERE (http://www.youtube.com/watch?v=qj3NY2jwDEo)

PICS
http://i52.tinypic.com/15wh1es.jpg
http://i56.tinypic.com/2aerznc.jpg
http://i51.tinypic.com/fnva1e.jpg

My question is how does all this look when you have a foldable rear sight and a fixed front sight?

Singlestack Wonder
03-30-11, 20:24
I thought I would throw up some pictures (since I'm more of a visual learner and this took me a while to get through my thick skull) to give folks a better idea on what the irons and rds looks like together and in terms of different sized mounts.

None of these pics are mine, I do not take credit for their work but appreciate every one of them, some are from users on calguns.net, another one of the pics is from ar15.com, and of course larue, or maybe another user from here, can't remember I apologize if one of these are yours and I did not mention you.

Here's a vid as well VID HERE (http://www.youtube.com/watch?v=qj3NY2jwDEo)

PICS
http://i52.tinypic.com/15wh1es.jpg
http://i56.tinypic.com/2aerznc.jpg
http://i51.tinypic.com/fnva1e.jpg

My question is how does all this look when you have a foldable rear sight and a fixed front sight?

The same if the rear folding sight is up.

Blkgunuser
11-05-11, 00:15
I thought I would throw up some pictures (since I'm more of a visual learner and this took me a while to get through my thick skull) to give folks a better idea on what the irons and rds looks like together and in terms of different sized mounts.

None of these pics are mine, I do not take credit for their work but appreciate every one of them, some are from users on calguns.net, another one of the pics is from ar15.com, and of course larue, or maybe another user from here, can't remember I apologize if one of these are yours and I did not mention you.

Here's a vid as well VID HERE (http://www.youtube.com/watch?v=qj3NY2jwDEo)

PICS
http://i52.tinypic.com/15wh1es.jpg
http://i56.tinypic.com/2aerznc.jpg
http://i51.tinypic.com/fnva1e.jpg

My question is how does all this look when you have a foldable rear sight and a fixed front sight?

Thanks for this AWSOME pictorial of an explanation. http://www.m4carbine.net/images/smilies/new/dance3.gifI know it's LaRue's stuff, but I was not aware of it myself. There should be no reason anybody should not get this topic by now. This is my first post here. I've been a lurker (registered member and not) for a couple of years now. And this 1/3 witness/co-witness has been going on toooo long already. Please sticky this picture up for those who cannot visually obtain the concept through verbal description. http://www.m4carbine.net/images/smilies/new/suicide.gif

This site has provided me with an enormous amount of information and has assisted me in my weapon(s) and accessories selection. I want to thank everybody again for a great site/tool to refer to for REAL help. :)

sspro2340
11-05-11, 00:39
Thanks for this AWSOME pictorial of an explanation.


No problem man, glad it helped

I remember it took me awhile to grasp the concept.

The above items posted were the sort of poignant moments that totally turned on the light bulb and lit up the entire valley for me

Doc Glockster
11-30-11, 17:30
http://i52.tinypic.com/15wh1es.jpg


For the life of me I cannot get the different elements to line up this way. I tried it with both eyes open and I think with one eye closed if I'm not mistaken.

I am using an Aimpoint T-1 w/LRP Mount & Spacer. I have tried getting the sight pictures in that pic with a Daniel Defense DD 1.5, a LaRue quick detachable fixed rear sight (the number escapes me right now), and the LMT M16A2 style rear sight (the one that looks like the chopped carry handle).

I have not been to the range to zero anything yet. I've just been experimenting with whether or not to go with folding or fixed rear sight and so I've been trying out different rear sights and the resulting sight pictures.

It seems that if the dot is centered in the Aimpoint then the dot is above the front sight post (fine since the rear BUIS is not being used), and the loop of the rear sight is canted. Then when I lower my head to look through the rear aperture, nothing remains lined up and I have to re-orient everything to get the dot centered, etc.

What am I doing wrong?

Will this tend to correct itself when I get the irons and the Aimpoint zeroed?

I wear pretty thick glasses, so I appreciate being able to hold my head high to see the dot in the Aimpoint. I also appreciate being able to "index" the dot to the front sight post although I understand some people say you shouldn't or shouldn't have to do this. But it's not going to do my any good to zero all the elements together unless I can get a good sight picture with the dot centered in the irons.

I was told years ago by an eye doctor that my eyes do not work together so I'm wondering if that's my answer right there.

Right now I'm ready to concede that the irons on my carbine will only be used if the red dot goes down, but I was really wanting to try out a cowitness.

Anybody? Am I doing something wrong?

ArmaGlock
12-07-11, 21:53
For the life of me I cannot get the different elements to line up this way. I tried it with both eyes open and I think with one eye closed if I'm not mistaken.

I am using an Aimpoint T-1 w/LRP Mount & Spacer. I have tried getting the sight pictures in that pic with a Daniel Defense DD 1.5, a LaRue quick detachable fixed rear sight (the number escapes me right now), and the LMT M16A2 style rear sight (the one that looks like the chopped carry handle).

I have not been to the range to zero anything yet. I've just been experimenting with whether or not to go with folding or fixed rear sight and so I've been trying out different rear sights and the resulting sight pictures.

It seems that if the dot is centered in the Aimpoint then the dot is above the front sight post (fine since the rear BUIS is not being used), and the loop of the rear sight is canted. Then when I lower my head to look through the rear aperture, nothing remains lined up and I have to re-orient everything to get the dot centered, etc.

What am I doing wrong?

Will this tend to correct itself when I get the irons and the Aimpoint zeroed?

I wear pretty thick glasses, so I appreciate being able to hold my head high to see the dot in the Aimpoint. I also appreciate being able to "index" the dot to the front sight post although I understand some people say you shouldn't or shouldn't have to do this. But it's not going to do my any good to zero all the elements together unless I can get a good sight picture with the dot centered in the irons.

I was told years ago by an eye doctor that my eyes do not work together so I'm wondering if that's my answer right there.

Right now I'm ready to concede that the irons on my carbine will only be used if the red dot goes down, but I was really wanting to try out a cowitness.

Anybody? Am I doing something wrong?

The first thing I'm going to tell you that might clarify things is that the Aimpoint is parallax free, simply stated, you don't have to center the dot inside of the optic. Just put the dot where you want to shoot.

You have the LRP with spacer which puts the iron sights in the bottom 1/3 of the optic glass, so when not looking through your rear sight the dot SHOULD be above the front sight post.

When you look through your rear sight, if your irons and optic have been zeroed to the same distance the dot should sit on the tip of the front sight and be centered (or close to it). I say close to it, because my dot has always sat on the tip, but just a little to the left of my front sight. That's on two separate rifles with different type iron sights. I have always zeroed my irons, brought the dot as close as possible and then zeroed the optic independently.

Hope this helps.

Doc Glockster
12-08-11, 10:08
The first thing I'm going to tell you that might clarify things is that the Aimpoint is parallax free, simply stated, you don't have to center the dot inside of the optic. Just put the dot where you want to shoot.

You have the LRP with spacer which puts the iron sights in the bottom 1/3 of the optic glass, so when not looking through your rear sight the dot SHOULD be above the front sight post.

When you look through your rear sight, if your irons and optic have been zeroed to the same distance the dot should sit on the tip of the front sight and be centered (or close to it). I say close to it, because my dot has always sat on the tip, but just a little to the left of my front sight. That's on two separate rifles with different type iron sights. I have always zeroed my irons, brought the dot as close as possible and then zeroed the optic independently.

Hope this helps.

It does, thanks.

I think this gets back to what I've complained about as "visual clutter." A person (me) focuses so much on the different sight elements lining up or not that they forget to consider the target. I know some trainers and some shooters have learned to insist on cowitness, but I think I may have to join the ranks of those who use a folding rear sight exclusively so that I'm more comfortable with the uncluttered sight picture. Too bad I wasted money on a couple of fixed rear BUIS's before buying the RDS. :(

ArmaGlock
12-08-11, 11:28
I think the flip-up vs. fixed is simply personal preference. Fixed sights work for some, but not for others when running an optic. I run fixed Troy sights and ran a Larue rear and standard FSB on my old rifle with an Aimpoint Comp C3. I just switched to an H-1 with Larue mount (1/3 also) and so far it's working well with fixed also. It didn't happen overnight, I've just learned to ignore the fixed over the 4 or 5 years I have been running them with the optic.

A good friend of mine runs flip-up Troys with his T-1 and is bothered by the "clutter" of fixed sights.

I think as long as you have a quality rear flip-up sight you are good to go. None of the instructors I have been to (Paul Howe, Frank Garcia, and local guys on my department with real world gun fight experience) have made a big issue about flip up sights, as long as you have some sort of quality BUIS. Not having them is frowned upon and a fail in my opinion if you use your rifle for self-defense or any other real world scenario.

Try selling the fixed sights you have and go with a flip-up rear sight.

I suggest zeroing them separately at the same distance and only worrying about them lining up when you look through the sights as a point of reference. Then do most of your shooting with your optic and occasionaly turn off the optic and shoot with your irons through the optic in order to stay proficient.

Just my .02.

Doc Glockster
12-08-11, 11:32
I suggest zeroing them separately at the same distance and only worrying about them lining up when you look through the sights as a point of reference. Then do most of your shooting with your optic and occasionaly turn off the optic and shoot with your irons through the optic in order to stay proficient.


Exactly! In my setup the flip up BUIS would only be used if the dot fails, but it's important to be able to sight through the window of the optic so you don't have to waste valuable seconds ripping the RDS off the rifle under fire.

I think we're on exactly the same page here.:thank_you2:

pbmaster2k89
12-29-11, 12:45
Correct me of I'm wrong, but from what I'm gathering, When u use say an aimpoint pro and line up the irons with the aimpoint (or even jus using the red dot) no matter where u aim ur sights at 0-100 yards, ur rounds will always hit ur mark?

blouzbee
01-10-12, 21:45
this was the thread i found when i was researching optics, i went lower 1/3 but it seems like less. thanks for the info

jbasas13
11-08-12, 00:02
im going with 1/3 cowitness i think it'll be a much clearer site picture when just using my optic.

Ledanek
02-18-13, 17:00
anyone know how to factory reset an Aimpoint micro H-1?
used on a BCM midlength over a LT660

I made serious fubu trying to zero it to permanent front sight post.
thanks

T2C
02-18-13, 17:53
im going with 1/3 cowitness i think it'll be a much clearer site picture when just using my optic.

I have been using lower 1/3 cowitness for about 15 years and I prefer it over absolute cowitness for that very reason.

aguila327
02-21-13, 11:11
anyone know how to factory reset an Aimpoint micro H-1?
used on a BCM midlength over a LT660

I made serious fubu trying to zero it to permanent front sight post.
thanks

I dont understand your question. Whst exsctly are you trying to reset?

Sent from my SCH-I535 using Tapatalk 2

AR15freak
12-06-13, 19:20
I never understood why some would want a lower 1/3 co witness. I only want to have one point of aim when I look through the scope, not two separate ones. BUIS means backup.. Point is that iron sights used to be the primary sighting system for fighting rifles, but now they are used more as a backup option should your red dot fail. Since the human eye picks up the red dot quicker than an iron sight post it makes sense to use it as your main sighting system.. However since the BUIS are in a fixed position on the rifle and don't move, you need to sight them in first, then align the red dot to the BUIS.. I have always done it that way, it was taught to me that way, and I believe that is the right way.. however others with far more experience than me may do things differently. If it works then more power to them.

TactTeam
12-06-13, 21:58
I never understood why some would want a lower 1/3 co witness. I only want to have one point of aim when I look through the scope, not two separate ones. BUIS means backup.. Point is that iron sights used to be the primary sighting system for fighting rifles, but now they are used more as a backup option should your red dot fail. Since the human eye picks up the red dot quicker than an iron sight post it makes sense to use it as your main sighting system.. However since the BUIS are in a fixed position on the rifle and don't move, you need to sight them in first, then align the red dot to the BUIS.. I have always done it that way, it was taught to me that way, and I believe that is the right way.. however others with far more experience than me may do things differently. If it works then more power to them.

I still use the Field Zero method you talk to get zeroed with a new red dot. Then I fine tune the red dot by zeroing by itself.

I have absolute co-witness on my personal rifle that doesn't have a DBAL on it. With the DBAL I like the lower 1/3 because the sight picture is less cluttered. If it goes down its still a quick transition.

Kissel
12-07-13, 12:25
Agree with Dano5326. Cowitness RDS and irons only works with low mounts made for that purpose. Simple geometry tells you that a high mount won't (and isn't supposed to) work that way.

Ripdog33
12-27-13, 08:38
I never understood why some would want a lower 1/3 co witness. I only want to have one point of aim when I look through the scope, not two separate ones. BUIS means backup.. Point is that iron sights used to be the primary sighting system for fighting rifles, but now they are used more as a backup option should your red dot fail. Since the human eye picks up the red dot quicker than an iron sight post it makes sense to use it as your main sighting system.. However since the BUIS are in a fixed position on the rifle and don't move, you need to sight them in first, then align the red dot to the BUIS.. I have always done it that way, it was taught to me that way, and I believe that is the right way.. however others with far more experience than me may do things differently. If it works then more power to them.

on lower 1/3, Me personally, I do not like flip up sights. I have some on my work gun because I am told what to use. My personal gun has Troy HK style (Rounded hood) battle sights fixed. I like them much more than std ar front sight post (V type). Having fixed front and rear, lower 1/3 is much better or has a cleaner view. It works for me and i really like it. It may not or does not have to work for you but you may want to try it. Not just a few shots but run it for a while.

IMO, co witness does not mean they meet eachother when sighting, it simply means, viewed together (inside the RDS window).

GunBugBit
01-05-15, 12:04
I use co-witnessing as a tool to get a newly-mounted red dot in the neighborhood of the already-zeroed irons before I go out to fine-tune the red dot.

Then, I fine-tune-zero the red dot independently.

I don't worry about keeping my irons and red dot in agreement, especially when using a quick-detach mount for the dot. If my dot fails, I will detach it and use the irons. If for some unforeseen reason I'm forced to aim the irons through the glass because I don't have time or am otherwise unable to remove the glass, then my approach is obviously not optimal in the cases where the glass slightly shifts the iron picture.

If my red dot and irons agree after I've zeroed them independently, great, but I don't expect them to agree.

In other words, I treat the two aiming systems as independent systems that I use and zero independently.