Muzzle flash is the light — both

visible Visibility, in meteorology, is a measure of the distance at which an object or light can be seen. Visibility may also refer to: * A measure of turbidity in water quality control * Interferometric visibility, which quantifies interference contrast ...

and infrared — created by a muzzle blast, which is caused by the sudden release and expansion of high-temperature, high-pressure gases from the muzzle of a

firearm A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes ...

during shooting. Both the blast and flash are products of the

exothermic In thermodynamics, an exothermic process () is a thermodynamic process or reaction that releases energy from the system to its surroundings, usually in the form of heat, but also in a form of light (e.g. a spark, flame, or flash), electricity (e ...

combustion of the

propellant A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the e ...

( gunpowder), and any remaining unburned powders reacting with ambient air. The size and shape of the muzzle flash is dependent on the combustion energy of

being used, the amount of combustible

ejecta Ejecta (from the Latin: "things thrown out", singular ejectum) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic materials (tephra) that came out of a volcanic explosion and magma ...

remaining, and any devices attached to the muzzle (such as a flash hider, suppressor or muzzle shroud).

Characteristics

Muzzle flash can be broken down into five distinct components. *The ''muzzle glow'' is a reddish glow that is visible before the

bullet A bullet is a kinetic projectile, a component of firearm ammunition that is shot from a gun barrel. Bullets are made of a variety of materials, such as copper, lead, steel, polymer, rubber and even wax. Bullets are made in various shapes and co ...

leaves the

barrel A barrel or cask is a hollow cylindrical container with a bulging center, longer than it is wide. They are traditionally made of wooden staves and bound by wooden or metal hoops. The word vat is often used for large containers for liquids, ...

. It glow is created by superheated gases that have leaked past the projectile and have exited the barrel ahead of it. *The ''primary flash'' is caused by superheated propellant gases exiting the firearm behind the projectile, which radiates its energy to the surroundings partly as visible light. Although amongst the brightest of the flashes, the heat of the primary flash dissipates very quickly, and thus is usually not distinctly noticeable. *The ''intermediate flash'' is caused by shock waves created by the high speeds of the escaping gases and projectile, and appears as a reddish disc-shaped in front of the muzzle. *The ''secondary flash'' appears farthest from the muzzle as a large white or yellow

fireball Fireball may refer to: Science * Fireball (meteor), a brighter-than-usual meteor * Ball lightning, an atmospheric electrical phenomenon * ''Bassia scoparia'', a plant species Arts and entertainment Films * ''The Fireball'', a 1950 film starring ...

, and is caused by a newly ignited oxidation of incompletely combusted

when mixed with abundant oxygen in the surrounding atmosphere. *Following the dissipation of the muzzle flash, partially unburnt powder or other heated materials (e.g. dislodged lead, copper and/or carbon foulings) can be further ejected from the muzzle and appear as airborne residual '' sparks''.

Detection

Muzzle flashes create distinct signatures that can be located using infrared imaging technology. Technology is being developed to detect enemy muzzle flashes before the projectile reaches its target.

Suppression

Muzzle flash, particularly the longer-duration secondary flash, is an inherent problem in most firearms. Due to its brightness, muzzle flash can temporarily blind the shooter, or give away the shooter's location, especially at night. Ingestion of the muzzle flash from aircraft-mounted guns has also been implicated in compressor stall and flameout, causing loss of aircraft. Flash hiders attempt to suppress the flash mechanically, by interfering with the blast wave using either a cone or a series of slots at the muzzle of the firearm. However, since the primary cause of the secondary flash is combustion of hydrogen and carbon monoxide, chemical approaches are also used. In World War I, bags of

sodium chloride Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35.45 g ...

(table salt) were placed in front of the propellant charges of artillery to suppress the flash. Addition of a few percent of alkali salts to the powder for flash suppression is common, typically salts of potassium such as

potassium chloride Potassium chloride (KCl, or potassium salt) is a metal halide salt composed of potassium and chlorine. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water, and its solutions have a salt ...

, potassium sulfate, potassium carbonate and potassium bicarbonate. In both cases, the salts act as catalysts, and interfere with the hydrogen-oxygen combustion to reduce the muzzle flash. The side effects of the alkali salts are a reduction in power, an increase in smoke, and fouling and corrosion of the firearm and nearby equipment (a significant concern with aircraft guns). Ammonium chloride and ammonium nitrate salts have also been tried with success. Silencers, while designed to mitigate the loud sound of gunfire, can also suppress muzzle flash. This is done by trapping and delaying the expansion of the propellant gases with containing multiple sound baffles, which slows the gases and dissipating their energy over a larger surface area before releasing them at a cooler temperature. The enclosure of the silencer can also serve as a muzzle shroud to physically conceal any light emitted by the gases and residuals.

References

External links

High-speed photographs
of shotgun muzzle blasts
Tutorial on how to add muzzle flares to a gun
{{DEFAULTSORT:Muzzle Flash Firearm terminology Light sources Noise es:Bocacha apagallamas

Characteristics

Detection

Suppression

See also

References

External links