Just out of curiosity, are all of you guys who are returning your Eotechs dissatisfied with them?
What kind of temp. extreme are we talking about to get the POI shift?
I have not fully committed to sending mine back for a return, but probably will. My Eotech was rock solid in terms of POI for several years, but then again, it was primarily used at indoor ranges, and outdoor ranges in fair weather (65-80 deg). No POI shift.
Two winters ago, I took the rifle out during a chillier day (just at the freezing mark - around 32 deg F) - dry, no wind, just a bit brisk. The POI was a bit off - a bit, but noticeably. Adjusted it at the range. Checked my mounting to be sure it was off.
Following week, back to the balmy indoor range - POI was off again. Adjusted again. Back of my mind, I'm wondering what gremlins are playing with my optics. Call the temperature indoors in the 68-72 deg range ...
Outdoors shortly thereafter on an even chillier day (light flurries), and the POI was off yet again.
At this points the EoTech was retired (though I very much like their reticle), in favor of an Aimpoint Pro.
Near as I can figure, the Eotech needs to be zeroed in approximately the same temperature range as it is used. But, having to re-zero to accomodate a temperature swing of +/-40 degrees seems pretty delicate - for military gear.
I like the reticle so much, I was willing to keep it as a purely fair weather/indoor range optic on on rifle, and the Aimpoint pro on a second rifle for more varied use. But, I'm rethinking that...