http://soldiersystems.net/2015/09/30...ystems-eotech/
While there is a great deal of information in the SOUM, two glaring issues stick out. The first is the reliability of the HWS in extreme temperatures, referred to as “Thermal Drift”. The PMO has noted a +/- 4 MOA shift at -40 Deg F and 122 Deg F. Second, is the concern over the claim by EOTech that their HWS are parallax free which was the subject of a previous Safety of Use Message from the same office issued 16 March, 2015. In this case they noted between 4 and 6 MOA parallax error depending on temperature conditions. Despite the PMO working with EOTech to rectify the issues, they still have not been resolved.We've experienced issues with our agency EO-techs for some time. Not all of them but enough that i'm eagerly awaiting our new H-1's.EOTech Updates User Manuals
EOTech seems to have officially backed off their previous claims regarding operational temperature ranges as well as parallax free attributes. Upon investigation, we noted that EOTech had changed the public specs for their HWS. Specifically, they published new manuals in June, 2015 which are available from the individual product listing pages on their website.