Sight Alignment of a Shotgun
Shotguns do not usually have rear sights. Most have a bead at the muzzle end, and a ventilated rib on top of the barrel leading up to the bead. When pointing a shotgun at a target, the rib and front bead should be aligned so that you are looking straight down the barrel, to properly hit the target. If the bead appears to be higher or lower than the rib, then you are not looking straight down the barrel, and the shot will not hit the intended target.