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Thermal Drift problem with EOTech...? UPDATE 25 Jan 16

Posted: Wed Sep 30, 2015 9:43 am
by ELB
If you have or are contemplating getting an EOTech sight, this might be of interest to you:

USSOCOM Issues Safety of Use Message for EOTech Enhanced Combat Optical Sights – Plus More Goings On
...
Important Information
Thermal Drift - After zeroing the ECOS systems at or near ambient temperature (73°F), the zero position will shift during operating temperature changes. The ECOS systems have the potential to shift approximately +/- 4 Minutes of Angle (MOA) at -40°F and 122°F. Due to thermal drift, the sight may not return to zero. The systems have the potential of approximately a +/- 2 MOA zero shift upon return to ambient (73°F) after being exposed to any temperature between -40°F and 122°F temperatures. Impact to the operators is the sight zero will be affected at varying operating temperatures. Please refer to below table to determine the MOA effect in inches based on target range:
...
See http://soldiersystems.net/blog1/wp-cont ... 5-Copy.pdf for the table and the rest of the safety message.

ETA new info on 25 Jan 16: https://primaryandsecondary.com/eotech- ... ce-issues/

Re: Thermal Drift problem with EOTech...?

Posted: Wed Sep 30, 2015 11:43 am
by LSUTiger
Only specific models are affected according to the article. At least that's the way I read it.

I have an Eotech 512 NSN 1240-01-554-4488 and Eotech 552 NSN 1240-01-492-5264 which is not listed specifically.

The only confirmed issue I've had with Eotech is that I went to inspect the 512 recently and the lithium battery was dead. I had only used it 20 hrs or so. The batteries have a 2025 date on them but were dead after a couple of years. Is it the batteries or is it the Eotech? Is it to be expected?

On the 552 the batteries worked fine.

Both reticles get faint when the approach the edges of the window. I don't recall this happening before. I wonder if this is a problem? Is this a nitrogen leak? I'm gonna call Eotech and see what they say.

I love the Eotech Reticle but I was already in the process of switching to Aimpoint.


http://www.eotechinc.com/ NSN info is in user manuals.

https://www.armyproperty.com/ for NSN info

Re: Thermal Drift problem with EOTech...?

Posted: Wed Sep 30, 2015 1:29 pm
by ELB
LSUTiger wrote:Only specific models are affected according to the article. At least that's the way I read it.

I have an Eotech 512 NSN 1240-01-554-4488 and Eotech 552 NSN 1240-01-492-5264 which is not listed specifically...
I see that. I wonder how many components the 512 and 552 share with the others, and if they just haven't tested those yet, or are still in the testing process? They may be doing only the ones that were on a specific contract, or that had garnered enough field complaints to start an investigation. I would bet down the road they will insist that EOTech prove, by analysis if nothing else, that any EOTech with an NSN is either not affected or repaired/redesigned.

Re: Thermal Drift problem with EOTech...?

Posted: Wed Sep 30, 2015 1:37 pm
by MechAg94
I tried to use a clamp-on fore grip rail on an M1 Garand once. The EOTech I tried got pretty warm after a few shots. I ended up taking it off as I figured the heat wouldn't do it any good. I have other guns to put a red dot on these days. At least I didn't have to modify the rifle to do it.

Re: Thermal Drift problem with EOTech...?

Posted: Wed Sep 30, 2015 2:19 pm
by Mike S
LSUTiger wrote: I have an Eotech 512 NSN 1240-01-554-4488 and Eotech 552 NSN 1240-01-492-5264
Have you noticed parallax with either of those?

Re: Thermal Drift problem with EOTech...?

Posted: Wed Sep 30, 2015 2:38 pm
by LSUTiger
Mike S wrote:
LSUTiger wrote: I have an Eotech 512 NSN 1240-01-554-4488 and Eotech 552 NSN 1240-01-492-5264
Have you noticed parallax with either of those?
I haven't noticed it.

but there are some youtube videos that show it

https://www.youtube.com/watch?v=waeYp90OpHk

Re: Thermal Drift problem with EOTech...?

Posted: Thu Oct 01, 2015 4:12 pm
by LSUTiger
I re-inspected my 512 and 552. The 552 is working fine but the 512 definitely has a reticle fade problem. I requested and RMA and go a response from Eotech to send it in 30 days for repair free of charge. It's a 5 year old unit. Barely used. But out of warranty I'm sure. So free is a nice surprise.

Re: Thermal Drift problem with EOTech...?

Posted: Thu Oct 01, 2015 5:40 pm
by MadMonkey
Reaffirms my decision to sell my EOTech and stick with Aimpoint for my red dots. There's a new optic that should be available soon which has a similar reticle as the EOTech but at a cheaper price... can't remember the name though. Seems that's the reason most people like EOTech anyway.

The battery life is my biggest gripe, they don't last long at all in my experience, at least compared to Aimpoint (or even the PA Microdots I have on my 22s, or the Fastfires I have on my pistol and shotgun).

Re: Thermal Drift problem with EOTech...?

Posted: Thu Oct 01, 2015 5:56 pm
by C-dub
LSUTiger wrote:
Mike S wrote:
LSUTiger wrote: I have an Eotech 512 NSN 1240-01-554-4488 and Eotech 552 NSN 1240-01-492-5264
Have you noticed parallax with either of those?
I haven't noticed it.

but there are some youtube videos that show it

https://www.youtube.com/watch?v=waeYp90OpHk
That MSE sight looks nice at $600+. My EO is not on that list, so until it wears out or I need something for another rifle, that I also don't have yet, I'll wait.

Re: Thermal Drift problem with EOTech...?

Posted: Fri Oct 02, 2015 10:34 am
by Topbuilder
I have had the XPS2-1 for several years. I really like it. After watching the video comparing the different sights, I see I am at a disadvantage with the single dot, as far as canting goes. The comparison also "highlighted" the EOTech for giving off a glow in low light situations. Something I will have to look into... As far as the battery debate goes, I read a post where the EOTech was being trashed and his Aimpoint was praised for long battery life. Then he adds "I replace the battery every year. $5 is cheap insurance." That seems to kill the argument but, that is what I have done also. Every January, the smoke detectors and the EOTech get new batteries.

Re: Thermal Drift problem with EOTech...?

Posted: Fri Oct 02, 2015 11:22 am
by TexasVet
MadMonkey wrote:There's a new optic that should be available soon which has a similar reticle as the EOTech but at a cheaper price... can't remember the name though. Seems that's the reason most people like EOTech anyway.
The reticle is why I like the EOTech, (65 MOA circle is a good offset for short range) plus using AA batteries. I have looked at the Mepro Tru-Dot RDS (has built in QD attachment), but it is a single dot. What is the other optic with the similar reticle ?

Re: Thermal Drift problem with EOTech...?

Posted: Fri Oct 02, 2015 12:06 pm
by LSUTiger
C-dub wrote:
LSUTiger wrote:
Mike S wrote:
LSUTiger wrote: I have an Eotech 512 NSN 1240-01-554-4488 and Eotech 552 NSN 1240-01-492-5264
Have you noticed parallax with either of those?
I haven't noticed it.

but there are some youtube videos that show it

https://www.youtube.com/watch?v=waeYp90OpHk
That MSE sight looks nice at $600+. My EO is not on that list, so until it wears out or I need something for another rifle, that I also don't have yet, I'll wait.
It might still be available some places but I checked on Optics Planet and it said it was discontinued by the manufacturer.

http://www.opticsplanet.com/mse-red-dot ... lable.html

I have found the same on other websites as well. So IDK if they the company is still around.

Re: Thermal Drift problem with EOTech...?

Posted: Sat Oct 10, 2015 7:35 pm
by MadMonkey
TexasVet wrote:
MadMonkey wrote:There's a new optic that should be available soon which has a similar reticle as the EOTech but at a cheaper price... can't remember the name though. Seems that's the reason most people like EOTech anyway.
What is the other optic with the similar reticle ?
You made me dig through my history and find it ;-)

http://www.thefirearmblog.com/blog/2015 ... ot-review/

The reticle isn't exact, but it's similar. I kinda like it.

Re: Thermal Drift problem with EOTech...?

Posted: Fri Dec 25, 2015 7:16 pm
by Jose_in_Dallas
So I picked up an EOTech EOTech EXPS3-4 with the 3X Magnifier a couple of weeks ago knowing that there might possibly be a problem but wasn't sure on what models were affected. In looking at the various documents online, the closest I see listed to my model is the EOTech EXPS3-0. I'm guessing this is basically the same as my model and therefore mine is affected?

Re: Thermal Drift problem with EOTech...?

Posted: Sat Dec 26, 2015 10:01 am
by lfinsr
Jose_in_Dallas wrote:So I picked up an EOTech EOTech EXPS3-4 with the 3X Magnifier a couple of weeks ago knowing that there might possibly be a problem but wasn't sure on what models were affected. In looking at the various documents online, the closest I see listed to my model is the EOTech EXPS3-0. I'm guessing this is basically the same as my model and therefore mine is affected?
As far as I can tell they're all affected. I chose to pursue the return and am now wrestling with what I want as a replacement.

They are accepting returns no questions asked but I've not heard of anyone actually receiving their refund yet. Time will tell how long it takes before they actually mail a check.

There's also a class action suit in the works. Might want to check in there as well...