I'm working on an article on the police use of red-dot sights. I own several, but my experience level with these optics is still very limited. Does anyone know, if, once a handgun (or long arm) is sighted-in using a red-dot optic, is the firearm now sighted-in for anyone picking it up? My guess would be, "yes." On the other hand, there may be elements in play which I am unfamiliar with. Thanks all!