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How to Zero an Eotech when you get it out of whack !!

14465 Views 7 Replies 6 Participants Last post by  MickeyC
How do I mechanically zero my sight?
The sight has 40 MOA (Minutes Of Angle) of travel in every direction from center. This means a complete range of 80 MOA from extreme left to the extreme right range of adjustment. The same range of adjustment is true for the elevation; so 80 MOA from top to bottom.

Since each click or adjustment of the shaft moves the reticle .5 (or 1/2) an MOA, that means there are 160 clicks from extreme left to extreme right (same for top to bottom).

To rezero the sight, adjust the reticle to one end of the extreme (left or right). You will feel a sudden resistance and a limitation in your ability to move the shaft once you reach the extreme. DO NOT ATTEMPT TO ADJUST THE SHAFT IN THE SAME DIRECTION. This will result in a seizure of the windage or elevation shafts, and cause the sight to be inoperable.

Once at that extreme, turn the shaft in the opposite direction 80 clicks. This will move the reticle 40 MOA back to center. Complete the same process for the elevation (top to bottom) and the sight will be re-zeroed.
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Just curious, why would you want to do this?
When you screw up and zero your Eotech and then take it off the gun and re-mount it.

They lose zero if you simply mount them on the rail. So I got mine all F'd up so I started from scratch and when I would give it 5 or so clicks I didn't notice the reticle moving at all. Well when there is 160 clicks for windage and 160 for elevation you need to click away until the reticle moves .

I thought the damn thing was broken until I followed this procedure...now all I have to do is set the red dot on top of the front sight post and co-witness.

That should get me at least on paper...then I can fine tune.
I'm about to find out what happens when you take an ACOG off and put it back on. I removed the ACOG from my XCR to make the cutouts for my Pelican case and plan to try it on my new FAL before putting it back on the XCR.

When I first got the ACOG I mounted it on the rail on the XCR and discovered at shorter ranges, around 25 yds, it was right on and I didn't need to make any adjustments. Naturally I have the unrealistic hope that I'll be able to put it back on without having to make any changes. Of course I didn't put it through 100yd paces to see if I needed to adjust it before and do plan to do that now. But it will be interesting to see how close it is at the shorter ranges. BTW, I have the TA31F which has the thumbscrew rail attachment built in.
I take my Eotech off every time I go to the range and I have never had to re-zero. It has always been on target.
I sight in my BUIS, then get the EOTECH to match. Always gives me a return to zero point.
By following those instructions how is the EOTech zero'ed? The recticule is mechanically centered, but not zero'ed. I was under the impression that to be zero'ed the point of aim needs to be the point of impact.

In conjuction with my GG&G Accucam, my 551 has never been more than .50 moa off from zero when remounting. The key is to make sure you mount the unit at the same T-mark each time (obviously) and to push the unit forward or backwards in the slot (depends which way you pushed it during the original zero). There is a certain amount of movement the EOTech has since the design does not incorporate a recoild lug. Measure the diameter of the thumb screw and the distance between the cross slots. You will be surprised.
The other thing to remember with an EOTech is that it's not a precision sight. Your XCR will shoot 1-1.5 MOA at 100 yards. From memory the EOTech adjustment is 0.5 MOA. It's designed for combat shooting and not precision marksmanship.

If it helps, I sight my XCR at 50 yards. This then gives me the same point of aim, within a couple of inches, out to 200 yards. Beyond 200 I turn off my EOTech and use iron sights though the window. Also the EOTech hasn't come off my rifle since the day I mounted it. There simply hasn't been any need to remove it.
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