Interestingly, I have noticed that the way one carries/wears the exact same bag can make a difference. The Safepacker, made and sold my The Wilderness dot com, is actually made specifically to carry a handgun, but nothing on its exterior is overtly “tactical.” If I wear it on my belt, near either hip, I get a much different reaction than if I hand-carry it, or wear it on a strap, cross-body-bag style.
I have an Eagle Industries Discreet Carbine Case, made specifically to hold a collapsible-stock AR15, but if I am visibly carrying a serious camera, the carbine case rarely gets a second glance, as everyone seems to assume I have a tripod inside the case. Of course, serious cameras are not welcome, inside many places, so one has to allow for that policy/prejudice. (Actually, I have, indeed, used the case far more often to tote a tripod, than an AR15.)