AR15.Com Archives
 What distance do i zero my new eotech?
motocam25  [Team Member]
10/11/2009 4:37:14 PM
Mounted new Eotech on YHM riser. Shooting M&P 15
Narc45ACP  [Team Member]
10/11/2009 4:52:51 PM
50 yards.
shrapmagnet  [Member]
10/11/2009 5:04:39 PM
We zero the eotech at 25 meters, you should fire a group no greater than 1.5 inches at this distance. The group should impact 1.5-1.1.75 inches BELOW the point of aim, giving the best zero from 5-200 meters. At 25 meters, 8 clicks of adjustment will move the point of impact approx. 1 inch.
Hero  [Team Member]
10/11/2009 5:42:06 PM
If you are cowitnessing, then zero it at the same distance as your irons.

I go 50 yards.
motocam25  [Team Member]
10/11/2009 5:45:24 PM
If I zero at 50, where will I be at 100?
Molon  [Team Member]
10/11/2009 5:58:21 PM
Originally Posted By shrapmagnet:
We zero the eotech at 25 meters, you should fire a group no greater than 1.5 inches at this distance. The group should impact 1.5-1.1.75 inches BELOW the point of aim, giving the best zero from 5-200 meters. At 25 meters, 8 clicks of adjustment will move the point of impact approx. 1 inch.


Hardly. An EOTech zeroed for a point of impact that is just 1.6” low at 25 meters will have a trajectory that never even crosses the line of sight. At 200 meters the point of impact will be more than 4” low.






OP, listen to the rest of the posters and zero at 50 yards.





Daisycutter123  [Team Member]
10/11/2009 5:58:40 PM
Originally Posted By motocam25:
If I zero at 50, where will I be at 100?


1.5' - 1.8' high, on at 200, about 2'' low at about 240. ETA - See above
Narc45ACP  [Team Member]
10/11/2009 6:55:11 PM
Originally Posted By Molon:
Originally Posted By shrapmagnet:
We zero the eotech at 25 meters, you should fire a group no greater than 1.5 inches at this distance. The group should impact 1.5-1.1.75 inches BELOW the point of aim, giving the best zero from 5-200 meters. At 25 meters, 8 clicks of adjustment will move the point of impact approx. 1 inch.


Hardly. An EOTech zeroed for a point of impact that is just 1.6” low at 25 meters will have a trajectory that never even crosses the line of sight. At 200 meters the point of impact will be more than 4” low.


http://www.box.net/shared/static/y9sngnc5m9.jpg



OP, listen to the rest of the posters and zero at 50 yards.

http://www.box.net/shared/static/lkjcnq0kkk.jpg





Nice one, Molon. Can you do a bullet drop curve for an Eotech zeroed at 100 yards? I want to check something out.
Molon  [Team Member]
10/11/2009 7:54:04 PM
Originally Posted By Narc45ACP:
Originally Posted By Molon:
Originally Posted By shrapmagnet:
We zero the eotech at 25 meters, you should fire a group no greater than 1.5 inches at this distance. The group should impact 1.5-1.1.75 inches BELOW the point of aim, giving the best zero from 5-200 meters. At 25 meters, 8 clicks of adjustment will move the point of impact approx. 1 inch.


Hardly. An EOTech zeroed for a point of impact that is just 1.6” low at 25 meters will have a trajectory that never even crosses the line of sight. At 200 meters the point of impact will be more than 4” low.


http://www.box.net/shared/static/y9sngnc5m9.jpg



OP, listen to the rest of the posters and zero at 50 yards.

http://www.box.net/shared/static/lkjcnq0kkk.jpg





Nice one, Molon. Can you do a bullet drop curve for an Eotech zeroed at 100 yards? I want to check something out.


After I posted, I started thinking the same thing. He was probably trying to obtain a 100 yard zero, but erroneously used 25 meters for 25 yards. There’s a big difference between the two when it comes to the downrange trajectories. It’s anyone’s guess were he got the 1.5" to 1.75” low concept from, (possibly for different mounts for the EOTech? But that specifically needs to be addressed for each mount, not as a generic instruction as again it makes a big difference downrange.)

If you’re going to use a zero that has a point-of-aim equals point-of-impact, at the maximum ordinate of the trajectory, (such as the 100 yard zero) you'd be much better off by zeroing at that distance.
Narc45ACP  [Team Member]
10/11/2009 9:45:52 PM
Originally Posted By Molon:
Originally Posted By Narc45ACP:
Originally Posted By Molon:
Originally Posted By shrapmagnet:
We zero the eotech at 25 meters, you should fire a group no greater than 1.5 inches at this distance. The group should impact 1.5-1.1.75 inches BELOW the point of aim, giving the best zero from 5-200 meters. At 25 meters, 8 clicks of adjustment will move the point of impact approx. 1 inch.


Hardly. An EOTech zeroed for a point of impact that is just 1.6” low at 25 meters will have a trajectory that never even crosses the line of sight. At 200 meters the point of impact will be more than 4” low.


http://www.box.net/shared/static/y9sngnc5m9.jpg



OP, listen to the rest of the posters and zero at 50 yards.

http://www.box.net/shared/static/lkjcnq0kkk.jpg





Nice one, Molon. Can you do a bullet drop curve for an Eotech zeroed at 100 yards? I want to check something out.


After I posted, I started thinking the same thing. He was probably trying to obtain a 100 yard zero, but erroneously used 25 meters for 25 yards. There’s a big difference between the two when it comes to the downrange trajectories. It’s anyone’s guess were he got the 1.5" to 1.75” low concept from, (possibly for different mounts for the EOTech? But that specifically needs to be addressed for each mount, not as a generic instruction as again it makes a big difference downrange.)

If you’re going to use a zero that has a point-of-aim equals point-of-impact, at the maximum ordinate of the trajectory, (such as the 100 yard zero) you'd be much better off by zeroing at that distance.


Damn, you read my mind! Do you have the curve for the 100 yards Eotech zero?
Molon  [Team Member]
10/11/2009 11:06:50 PM


Narc45ACP  [Team Member]
10/11/2009 11:12:32 PM


Thank!
Narc45ACP  [Team Member]
10/11/2009 11:20:57 PM


Yup, it does look like it would approximate his logic if he actually meant yards instead of meters.
Brahmzy  [Member]
10/12/2009 1:17:19 AM
I've always done 50yds.

I pretty much always hit whatever I need to out to 200 or so that way.
shrapmagnet  [Member]
10/12/2009 9:42:16 PM
Holy cow, I opened up a can of worms. What I did neglect to add was that after we achieve our zero we fire at known distance at 100m (plate) and 200m (Larue) , and 300m (maiden) and determine hold offs(all of this is done in full kit). 90% of our shooting occurs at ranges less than 100 meters, and probably 80% of that occurs within 25 meters. Nearly ALL of our shooting occurs in populated areas, in the dark, when the M4 is used. Additionally, sometimes longer ranges are not available for zero/test fire, it just depends where you are. This is the method I have and continue to bet my life on.