I have confirmed that the red dot on the FNX45 DOES work when not near any structure or object. However, as soon as you get close to any object while looking through the red dot sight, the reticle disappears. As for the RV1, at the time of this submission it was mounted on an MP5 and was experiencing similar issues as with the red dot on the FNX45. Have not had a chance to confirm if in fact the RV1 has the same issue as the FNX45 red dot, or any other sight for that matter