Flare gun A flare gun is a firearm that launches flares . It is typically used for signalling , as distress signal ling , for people at sea or from the ground to aircraft . It is not designed to function as a weapon . Types . The most common type of flare gun is a Very ( sometimes spelled Verey ) , which was named after Edward Wilson Very ( 1847 – 1910 ) , an American naval officer who developed and popularized a single - shot breech - loading snub - nosed pistol that fired flare s ( Very flares ) . They have a single action trigger mechanism , hammer action , center fire pin . Modern varieties are frequently made out of brightly colored , durable plastic . The older type of Very pistol , typical of the type used in the Second World War , are of one inch bore ( 26 . 5mm ) . These are still available and more recent longer barrel models can also fire parachute flares . Many newer models fire smaller 12 - gauge flares . In countries where possession of firearms is strictly controlled , such as the United Kingdom , the use of Very pistols as emergency equipment on boats is less common than , for example , the United States . In such locations , distress flares are more commonly fired from single - shot tube devices which are then disposed of after use . These devices are fired by twisting or striking a pad on one end , but the contents are otherwise similar to a round from a flare gun , although the flares themselves are much larger and can burn brighter for longer . Flare guns may be used whenever someone needs to send a distress signal . The flares must be shot directly above , making the signal visible for a longer period of time and revealing the position of whoever is in need of help . Use as weapons . While not intended as a weapon , flare guns have been used as such in some situations . In 1942 , a German pilot mistakenly landed at the Pembrey Airfield in Wales . The duty pilot , Sgt . Jeffreys , did not have a conventional weapon , so he grabbed a Very pistol and used it to capture the German pilot , Oberleutnant Armin Faber . Towards the end of World War I during the Final Offensive of the Sinai and Palestine Campaign , on 19 October 1918 a German aircraft was destroyed on the ground by firing a Very light into the aircraft . The D . F . W . two – seater was first seen in the air ; the first German aircraft since aerial fighting over Deraa on 16 and 17 September just prior to the beginning of the Battle of Sharon . The two – seater was forced to land and was destroyed after the German pilot and observer had moved to safety . In World War II , Germany manufactured grenades designed to be fired from adapted flare guns known as the Kampfpistole , or Sturmpistole in its final form . The weapon was designed to function as an anti tank weapon but failed to perform to expectations due to the minuscule amount of TNT carried in the hollow charge projectiles . In the latter stages of the Korean War , on November 2 of 1951 , Lieutenant Edward Mastronardi and his 28 - man platoon of the Royal Canadian Regiment were occupying a spur halfway between UN and Chinese lines known as the Song - gok . During the night of the 2nd - 3rd , Chinese infantry launched several attacks against the spur . During the second attack , Mastronardi personally shot two Chinese soldiers with his Inglis Hi - Power pistol , and killed a third with his flare gun .