Take this for what it's worth, from Time/Life's Special Forces and Missions book-
No effort was spared to increase the raid's chances. For example, the regular sights on the assault rifles-a post on the barrel that the shooter centers in the notch in the gun's carry handle-were useless in the dark, even with a quarter moon. At Eglin, Simon's best marksman could hit torso-size targets at 50 meters only 25% of the time. Better sights would be required.
In June, Meadows had attended a small-arms conference in California, where he noticed a new kind of night sight. Agreeing that this might be just what was needed, Simon instructed Meadows to order 2 of the $49.50 devices from the manufacturer-Armalite Corporation of Costa Mesa, California-and mount them for testing.
Using the Armilite Singlepoint sight, even the poorest marksman could consistently put all his rounds in a torso sized target at 75 meters. The only trouble was the mountings tended to work loose. This was solved with the generous use of electrician's Tape. Sights were ordered for each rifle.