Muzzle flashes create distinct signatures that can be located using infrared imaging technology. These gunshot location systems provide a fairly precise location of the source of a shot fired outdoors-99% to within 33 feet (10m) or better-and can provide it to police within seconds of the shot being fired. Systems to detect muzzle blast with microphones and triangulate the location where the shots were fired are commercially available, and have been installed in many high crime areas of large cities. Ammonium chloride and ammonium nitrate salts have also been tried with success. The side effects of the alkali salts is a reduction in power, an increase in smoke, and fouling and corrosion of the firearm and nearby equipment (a significant concern with aircraft guns). In both cases, the salts act as catalysts, and interfere with the hydrogen-oxygen combustion to reduce the muzzle 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 sulfate, potassium carbonate, and potassium bicarbonate. In World War I, bags of sodium chloride (table salt) were placed in front of the propellant charges of artillery to suppress the flash. However, since the primary cause of the secondary flash is combustion of hydrogen and carbon monoxide, chemical approaches are also used. įlash suppressors attempt to suppress the flash mechanically, by interfering with the shock wave using either a cone or a series of slots at the muzzle of the firearm. Ingestion of the muzzle flash from aircraft mounted guns has also been implicated in compressor stall and flameout, causing loss of aircraft. Due to its brightness, muzzle flash can temporarily blind the shooter, or give away the shooter's location, especially at night. Muzzle flash, particularly the long duration secondary flash, is an inherent problem in most firearms. Following the dissipation of the muzzle flash, partially unburnt powder or other heated materials can be ejected from the muzzle and appear as sparks.Secondary flash is caused by the mixture of fuel-rich gases and oxygen in the atmosphere surrounding the muzzle. The secondary flash appears farthest from the muzzle as a large white or yellow flame.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 shape in front of the muzzle.Although amongst the brightest of the flashes, the heat of the primary flash dissipates quickly and thus is no longer visible. The primary flash is caused by propellant gases exiting the firearm behind the bullet.Muzzle glow is created by superheated gases that have leaked past the projectile and have exited the barrel. Muzzle glow is a reddish glow that is visible before the bullet leaves the barrel.Muzzle flash can be broken down into five distinct components. Both heat and pressure can result in light being emitted. The muzzle flash refers to the light emitted by the muzzle blast, both visible light and infrared. Note the minor flash at the gap between cylinder and barrel. The force of the muzzle blast can cause damage to items near the muzzle, and with artillery, the energy is sufficiently large to cause severe damage to surrounding structures and vehicles. With big guns such as artillery, that danger can extend outwards a significant distance from the muzzle. Muzzle blasts can easily exceed sound pressure levels of 140 decibels, which can cause permanent hearing loss even with brief and infrequent exposure. This energy can also be harnessed by a muzzle brake to reduce the recoil of the firearm, or by a muzzle booster to provide energy to operate the action. Residual pressures at the muzzle can be a significant fraction of the peak chamber pressure, especially when slow burning powders or short barrels are used. The overpressure wave from the muzzle blast of a firearm can contain a significant amount of energy because it travels at an extremely high velocity. Suppressors help to reduce the level of sound of a firearm, by providing a large area for the propellant gas to expand and cool before release. The sound of a gunshot may have two sources the muzzle blast itself, and any sound produced by a transonic or supersonic projectile. Soldiers covering their ears while firing a 120-mm mortar Sound The auditory component, the sound of the muzzle blast, is important because it can cause hearing loss or give away the gun's position, while the non-auditory component, the overpressure wave, can cause damage to items near the blast. The muzzle flash is often broken down into two components, an auditory component and a non-auditory component.
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