Eotech's and Heat Issues From Sunlight....

Tactical Gear Optics & Mounts
1

I did search first and did find heat issues but it’s seemingly always tied to them being mounted on Ak’s.
Weapons:
Both are DI rifles.

Wife- 16" Carbine franken rifle. Eotech 512 mounted on receiver towards front, but not all the way. Fresh Duracell lithiums. Changed them about 4 days prior. Always turned off after use.

Mine- 16" Midlength Rock River. Eotech EXPS 2-2 mounted on receiver just past the midpoint. Relatively fresh Surefire CR123. Changed about a month before. Always turned off after use.

Weather conditions:
Mid 80s
Very sunny
12 p.m. or so, the sun was directly overhead
Shooting prone, on concrete and no shade

Shooting type:
Slow fire
10 round strings, 3-5 seconds between each shot

Rounds fired until failure: 30 or so

What happened:
My wife was shooting and told me she could not see the reticle anymore. I told her to adjust the brightness since maybe the sun moved or something along those lines, which isn’t uncommon with Eotechs and other red dots. She said it didn’t work. I looked and the reticle was there, but so faint it wasn’t useable. Not long after that, mine began doing the same thing. Roughly the same amount of rounds also.

We took a short break, came back and they were working again. I’ve had the 512 for years, somewhere around 10 years and this has never happened. I’ve had the EXPS for about 4 years and same thing. Never happened before. So it was odd and moreso irritating. Especially considering batteries were new, no issues with the compartments so on. The only solution I have is that the direct sunlight was heating up the unit’s and causing the problem. Anyone have this problem before? Yes I’ve emailed L3 to see what the deal is and if they have a fix or solution. After that, I really have to eat some crow. I was always the guy defending Eotech…

2

I had mine over 10 years. It never failed me. (even in 130* Iraq firing way more than 30 rounds) Then, just this summer… it did this. I had given it to my son and it blanked out at the range. I attributed it to 10 year old electronics, and sold it off.

3

We have over 200 Eotechs at work. Bought them in mostly in 2009 and 2011. We do have a few older ones in SWAT. I’ve had about 10 exhibit this issue of working fine and get dim during the course of fire or just blink off. Most are carried in the trunks of the cars. I haven’t payed any attention to it possibly being heat related. I always carry a spare Eotech in the truck to use the battery compartment with new batteries to try and get the unit up and running back on the line. Usually doesn’t work. Fortunately L3 has replaced all of them so far under warranty. I have two in the Armory now to send back. L3 just replaces the units and never say what the issue is. David

4

I had an EXPS2-2 that lost brightness. I believe the cause of the problem was a nitrogen leak. I sent it in and it was repaired for free.

5

Kind of related. Interesting to say the least.

http://soldiersystems.net/2015/09/30/something-is-amiss-at-l3-warrior-systems-eotech/

6

I can’t wait until everyone starts dumping them. It’s going to be awesome.