Spotting rifle
A spotting rifle or ranging gun is a small-calibre rifle used as a sighting device for artillery. The ballistics of the spotting rifle are matched to those of the artillery piece, so that if a shot from the spotting rifle lands on the target, it may be assumed that the main weapon will also do so. Anti-tank recoilless rifles Spotting rifles were most commonly used with recoilless rifles as anti-tank artillery, from the 1950s to the 1970s. These weapons are used for direct fire with line-of-sight visibility to the target. As recoilless rifles have a relatively low muzzle velocity and thus a high trajectory, accurate ranging is important An optical sight can measure the bearing to a target, but not easily or accurately measure the range. Optical rangefinders were too large for lightweight portable artillery, and the later development of laser rangefinders would in turn make spotting rifles obsolete. The British BAT series of 120 mm anti-tank recoilless rifles used a variety of sighting systems. The original BAT used a purely optical sight. The MoBAT, a lightweight and more portable version, had a 7.62×51mm NATO Bren light machine gun. The final version, the WOMBAT, used the same American Remington M8C