Iron Sight

Iron Sight

Iron sights are a system of shaped alignment markers (usually metal) used as a sighting device to assist in the aiming of a device such as a firearm, crossbow, or telescope, and exclude the use of optics as in telescopic sights or reflector (reflex) sights. Iron sights are typically composed of two component sights, formed by metal blades: a rear sight mounted perpendicular to the line of sight and consisting of some form of notch (open sight) or aperture (closed sight); and a front sight that is a post, bead, or ring. Civilian defensive, hunting, and police firearms usually feature open sights, while many military battle rifles employ aperture sights. On many firearms the rear sight is adjustable for elevation or windage.

The earliest and simplest iron sights are fixed and cannot be easily adjusted. Many iron sights are designed to be adjustable, so that the sights can be adjusted for windage and elevation. For precision applications such as hunting or sniping the iron sights are usually replaced by a telescopic sight. Iron sights may still be fitted alongside a telescopic sight and are referred to as Back Up Iron Sights (Acronym B.U.I.S).