By using a red dot sight on a shotgun, you can significantly increase your shooting speed and accuracy.
The most common way of achieving such a setup is by mounting the red dot sight on the shotgun rail, often referred to as the shotgun rib, with a suitable adapter. These can measure anywhere from 6 to 15 mm in width. Some red dot sight shotgun mounts are designed for a specific width whereas others can be adjusted to fit.
Several adapters with marks such as 6–15 mm (the ones designed by Henneberger, for example) require a gunsmith’s work should the user wish to make them compatible with a shotgun rib wider than 6 mm.
The red dot sight can be mounted anywhere on the rib – the placement often has to do with the preference of the user.
Some manufacturers, such as Burris, manufacture a special type of red dot sight mounts for shotguns, mounted between the stock and the receiver with a loop.
Mounting a red dot on an installed Picatinny rail is also possible. As shotguns have no pre-drilled bores, a gunsmith must drill the bores before an appropriate Picatinny rail can be mounted on the receiver of the shotgun.