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.
Iâm 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 nilâŚgroup size with the red dot is smaller than the irons, unless Iâm shooting a rifle-length sighted gun.
There are different offsets depending on Ammo types and Optics and Lasers.
In my Arm chair commando opinion:
The only right way to do this is to first sight in your BUIS(s) and then âco-witnessâ your dot/scope/whatever.
That way if you ever have an optic failure you know for certain your BUIS(s) are calibrated for POA.
itâs not different - itâs the same, at the distance both are sighted in, and as long as youâre 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.
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 oâclock, for a proper 300m BZO of that sight or optic/red dot.
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 âtrueâ co-witnessâŚ
Never got wrapped around the axle on that.
I like my Irons usable and within the Aimpoints field of view, but not dead centerâŚ
I think to many shooters get wrapped about where there Irons are within that field of viewâŚ
The way I look at itâŚIf Iâm 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 âainâtâ coming back up for a while, Iâm 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 BUISâs are like my Parking brake, as long as itâs in a familiar location, and I test it from time to time to see if it works⌠Iâm good to goâŚI donât really give it much more thought then thatâŚ
weâre saying the same thing in two different ways. but the difference is in the details.
i think thereâs 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, itâs different.
i believe your example above is when using the dot OVER the irons, not looking through them.
Ok, I only read halfâŚ
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?
MM and SF1911,
I guess I have some more shooting to do. I know that I donât shoot my optic while looking through the irons, since I havenât taught myself to use all that sighting stuff. Itâs 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.
if youâre looking through the irons, the eotech dot can be adjusted so that itâs on top of the front sight whether or not itâs in a LaRue mount or right on the flat top, assuming youâve adjusted the dot and irons to each other.
i just chatted with brett on the phone - weâre on the same page.
hereâs my .02 on the terms:
co-witness: to me, this just means that iâll 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 youâre 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. theyâre zeroâd for different ranges. in simple terms (to me) âco-witnessâ means âi can see my irons through my opticâ, regardless of how theyâre zeroâd.
absolute co-witness: i think some have accepted this to mean that the irons are centered in height in the tube/window. i donât think it matters - thatâs just how much of the irons you want in your sight picture when youâre 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, youâve 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), âabsolute co-witnessâ mean the dot is right on top of the front sight WHEN I LOOK THROUGH THE IRONS.
hereâs where the details (and confusion) comes in. if youâve 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 zeroâd at (letâs 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, youâve now introduced an offset to the dot +(as it âfollowsâ 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 youâve zeroâd 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.
yes, agreed, as they should be when âabsolute co-witnessedâ (which has nothing to do with center/lower third position).
So what you are saying MM is that if the dot isnât sitting on top of your irons then itâs 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 itâs almost always down. I CAN if I want, adjust my view so the dot sits on top of my front iron, but thatâs 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.
suicide, not sure if i understood what you meant. the dot is only âabsolute co-witnessedâ if itâs sitting on the front sight WHEN youâre 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, youâre just lining up your eye to where itâd be when looking through the rear sight if it were flipped up and you had them lined up.
when youâre 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 youâre using the dot, ignore the front sight and donât bother trying to put the dot on it.
Do the procedures in the Army FM work?
MM- yes, thatâs exactly what I was getting at. Itâs just that when I gave my interpretation and I first mentioned âabsoluteâ 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 isnât perfectly on top of the front. I think thatâs 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 thatâs due to the Eotechâs clamping system on the rail but then again, it should be centeredâŚ
Iâm rambling. Itâs friday and I just came from the barâŚ
OK⌠lets be clear folks of course you can move any Red Dot (EoTech, Aimpoint, etc.) so it lines up just on top of the front site when looking through irons(presumably zeroed).
This does not mean you have zeroed the red dot. It only means you have zeroed the irons and moved a dot atop. If the red dot is in the same plane(how high off the reciever), for example: fixed front, EoTech no riser, BUIS, you will be damn close to iron zero. If you have a riser on an EoTech, or a tall Aimpoint mount, you will not be zeroed.
When using the red dot there should be no relationship between the dot and the irons, and still when the dot is on target rds should hit. Viewing & shooting a properly zeroed red dot, with an off axis view(not lined up with irons), will still result in rds on target.
My understanding is that a âtrueâ cowitness is the irons and dot being aligned together as viewed though a iron sight picture. Iâve never seen the point in that, defeats the advantages of the dot.
Iâve heard the argument, that if the dot fails, you donât have to shift your head.
I have mine with a Larue mount, so the irons are on the bottom third, dot unobstructed.
Iâve 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.
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.
Thatâs what Iâve heard anyway.
the utility of a âabsolute/trueâ 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 doesnât have to be co-zeroâd 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 âone dot widthâ above the FSP, etc).
normally, youâd 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 isnât 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 youâll see a sharper, more distinct dot.
i think the point of brettâs 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 zeroâd independantly.
Co-zeroâd - i suggest discarding the terms âabsoluteâ or âtrueâ co-witness as theyâre 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 theyâre both zeroâd at.