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Transitional ballistics, also known as intermediate ballistics, [1] is the study of a projectile's behavior from the time it leaves the muzzle until the pressure behind the projectile is equalized, so it lies between internal ballistics and external ballistics. [2] [3] [4] [5]
Transitional ballistics is a complex field that involves a number of variables that are not fully understood; therefore, it is not an exact science. [6] When the bullet reaches the muzzle of the barrel, the escaping gases are still, in many cases, at hundreds of atmospheres of pressure. [3] Once the bullet exits the barrel, breaking the seal, the gases are free to move past the bullet and expand in all directions. This expansion is what gives gunfire its explosive sound (in conjunction with the sonic boom of the projectile), and is often accompanied by a bright flash as the gases combine with the oxygen in the air and finish combusting. [4]
The propellant gases continue to exert force on the bullet and firearm for a short while after the bullet leaves the barrel. One of the essential elements of accurizing a firearm is to make sure that this force does not disrupt the bullet from its path. The worst case is a muzzle or muzzle device such as a flash-hider that is cut at a non-square angle, so that one side of the bullet leaves the barrel early; this will cause the gas to escape in an asymmetric pattern, and will push the bullet away from that side, causing shots to form a "string", where the shots cluster along a line rather than forming a normal Gaussian pattern.[ citation needed ]
Most firearms have muzzle velocities in excess of the ambient speed of sound, and even in subsonic cartridges the escaping gases will exceed the speed of sound, forming a shock wave. This wave will quickly slow as the expanding gas cools, dropping the speed of sound within the expanding gas, but at close range this shockwave can be very damaging. The muzzle blast from a high powered cartridge can literally shred soft objects in its vicinity, as careless benchrest pistol shooters occasionally find out when the muzzle slips back onto their sandbag and the muzzle blast sends sand flying.[ citation needed ]
During the first part of the intermediate ballistics period the real velocity of the projectile increases. It is caused by the propellant gases exiting the muzzle. For that reason the real maximum projectile velocity (Vmax) is higher than the real muzzle velocity (Vr). The external ballistics uses so-called initial velocity Vo, which is not the same as the real muzzle velocity. The initial velocity Vo is calculated via an extrapolation of the decaying part of velocity curve to the position of the muzzle (to). The difference between these two velocities is visible in the chart. [7]
In addition to the process of "crowning" a barrel to ensure a clean and accurate exit of the bullet, there are a number of devices that attempt to harness the muzzle blast for various reasons.
Flash suppressors and sound suppressors are the most obvious devices that operate in the transitional ballistics realm. These both alter the flow of the escaping gas to reduce the effects of the muzzle blast. Flash suppressors introduce turbulence into the mixing of fuel-laden hot gases escaping from the muzzle and the surrounding oxygen-rich air, reducing combustion efficiency and thus reducing the size and brightness of the flash. Sound suppressors slow the expansion of gases, allowing it to cool and reducing the rate at which it escapes to prevent a shockwave from forming.[ citation needed ]
A recoil compensator is designed to direct the gases upwards at roughly a right angle to the bore, in essence making it a small rocket that pushes the muzzle downwards, and counters the "flip", or rise of the muzzle caused by the high bore line of most firearms. These are often found on "raceguns" used for action shooting and in heavy, rifle caliber handguns used in metallic silhouette shooting. In the former case, the compensator serves to keep the sights down on target for a quick follow-up shot, while in the latter case they keep the heavy recoil directed backwards, preventing the pistol from trying to twist out of the shooter's grip.[ citation needed ]
A muzzle brake is designed to redirect the muzzle blast backwards, and therefore counter the recoil of the bullet. Muzzle brakes tend to be found on larger firearms, such as magnum rifles and artillery. A well designed muzzle brake can significantly reduce recoil, turning a rifle that would otherwise be punishing to shoot into a far more tolerable experience. A good example may be seen on the M82 Barrett sniper rifle.[ citation needed ]
There are downsides to both recoil compensators and muzzle brakes. They direct more of the muzzle flash to the sides or back towards the shooter—this is especially true of muzzle brakes. While eye and ear protection should always be used when shooting, this is even more essential with the muzzle blast directed back towards the shooter. Brakes and compensators are often quite bulky, adding length, diameter, and mass to the muzzle end of the firearm where it will affect the firearm's handling worst. While a simple slot milled in the barrel, such as those used in Magna-Porting, will provide some benefit, efficient redirection of the gas flow requires large ports and baffles to deflect as much gas as possible. It is also highly inadvisable to fire sabot rounds like shotgun slugs or APDS rounds through a muzzle brake not designed for them.[ citation needed ]
A muzzle brake or recoil compensator is a device connected to, or a feature integral to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter recoil and unwanted muzzle rise. Barrels with an integral muzzle brake are often said to be ported.
Recoil is the rearward thrust generated when a gun is being discharged. In technical terms, the recoil is a result of conservation of momentum, as according to Newton's third law the force required to accelerate something will evoke an equal but opposite reactional force, which means the forward momentum gained by the projectile and exhaust gases (ejectae) will be mathematically balanced out by an equal and opposite momentum exerted back upon the gun.
Muzzle velocity is the speed of a projectile with respect to the muzzle at the moment it leaves the end of a gun's barrel. Firearm muzzle velocities range from approximately 120 m/s (390 ft/s) to 370 m/s (1,200 ft/s) in black powder muskets, to more than 1,200 m/s (3,900 ft/s) in modern rifles with high-velocity cartridges such as the .220 Swift and .204 Ruger, all the way to 1,700 m/s (5,600 ft/s) for tank guns firing kinetic energy penetrator ammunition. To simulate orbital debris impacts on spacecraft, NASA launches projectiles through light-gas guns at speeds up to 8,500 m/s (28,000 ft/s). FPS and MPH are the most common American measurements for bullets. Several factors, including the type of firearm, the cartridge, and the barrel length, determine the bullet's muzzle velocity.
A flash suppressor, also known as a flash guard, flash eliminator, flash hider, or flash cone, is a device attached to the muzzle of a rifle that reduces its visible signature while firing by cooling or dispersing the burning gases that exit the muzzle, a phenomenon typical of carbine-length weapons. Its primary intent is to reduce the chances that the shooter will be blinded in low-light shooting conditions. Contrary to popular belief, it is only a minor secondary benefit if a flash suppressor reduces the intensity of the flash visible to the enemy.
A gun barrel is a crucial part of gun-type weapons such as small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure gas(es) is used to propel a projectile out of the front end (muzzle) at a high velocity. The hollow interior of the barrel is called the bore, and the diameter of the bore is called its caliber, usually measured in inches or millimetres.
A gunshot is a single discharge of a gun, typically a man-portable firearm, producing a visible flash, a powerful and loud shockwave and often chemical gunshot residue. The term can also refer to a ballistic wound caused by such a discharge.
The .22 Long Rifle, also known as the .22LR or 5.6×15mmR, is a long-established variety of .22 caliber rimfire ammunition originating from the United States. It is used in a wide range of firearms including rifles, pistols, revolvers, and submachine guns.
Internal ballistics, a subfield of ballistics, is the study of the propulsion of a projectile.
A blank is a firearm cartridge that, when fired, does not shoot a projectile like a bullet or pellet, but generates a muzzle flash and an explosive sound like a normal gunshot would. Firearms may need to be modified to allow a blank to cycle the action, and the shooter experiences less recoil with a blank than with a live round. Blanks are often used in prop guns for shooting simulations that have no need for ballistic results, but still demand light and sound effects, such as in historical reenactments, special effects for theatre, movie and television productions, combat training, for signaling, and cowboy mounted shooting. Specialised blank cartridges are also used for their propellant force in fields as varied as construction, shooting sports, and fishing and general recreation.
A contact shot is a gunshot wound incurred while the muzzle of the firearm is in direct contact with the body at the moment of discharge. Contact shots are often the result of close-range gunfights, suicide, or execution.
A muzzle booster or recoil booster is a device fixed to the muzzle of a firearm, intended to harness the energy of the escaping propellant to augment the force of recoil on portions of the firearm. In spite of its name, a muzzle booster does not increase muzzle force or velocity but instead is usually used to improve the reliability and/or rate of fire of a recoil operated firearm. It was invented by Hiram Maxim in 1894.
Muzzle flash is the light — both visible 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 during shooting. Both the blast and flash are products of the exothermic combustion of the propellant (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 propellant being used, the amount of combustible ejecta remaining, and any devices attached to the muzzle.
The DSR-1 is a compact bolt-action sniper rifle designed, manufactured and marketed by the German company DSR-Precision GmbH and was also marketed by the German company AMP Technical Services as a specialized sniper rifle for police sharpshooters. It has been adopted by the German counter-terrorist unit GSG 9, as well as by other European special police units and agencies.
A muzzle blast is an explosive shockwave created at the muzzle of a firearm during shooting. Before a projectile leaves the gun barrel, it obturates the bore and "plugs up" the pressurized gaseous products of the propellant combustion behind it, essentially containing the gases within a closed system as a neutral element in the overall momentum of the system's physics. However, when the projectile exits the barrel, this functional seal is removed and the highly energetic bore gases are suddenly free to exit the muzzle and rapidly expand in the form of a supersonic shockwave, thus creating the muzzle blast.
The following are terms related to firearms and ammunition topics.
Muzzle rise, muzzle flip or muzzle climb refers to the tendency of a firearm's or airgun's muzzle to rise up after firing. It more specifically refers to the seemingly unpredictable "jump" of the firearm's muzzle, caused by combined recoil from multiple shots being fired in quick succession. It has an adverse effect on maintaining accuracy with using automatic weapons or rapid-firing semi-automatic firearms, as a moving muzzle can throw off the shooter's aim, causing subsequent shots to miss the intended target.
A muzzle shroud, linear compensator, blast shield, forward blast diverter or concussion reduction device (CRD) is a sleeve that attaches to and extends beyond the muzzle of a firearm in order to redirect some of the noise and concussion, or shock wave, from the muzzle blast forward and away from the shooter, and other bystanders, behind and to the sides.
Recoil operation is an operating mechanism used to implement locked-breech autoloading firearms. Recoil operated firearms use the energy of recoil to cycle the action, as opposed to gas operation or blowback operation using the pressure of the propellant gas.
Firearm propellants are a specialized type of propellant used to discharge a projectile through the barrel of a firearm. Mixtures of different chemical substances are often used to control the rate of gas release, or prevent decomposition of the propellant prior to use. Short-barrel firearms such as handguns necessitate faster-burning propellants to obtain sufficient muzzle energy, while long guns typically use slower-burning propellants. The pressure relationships between propellant chemical reactions and bullet response are described as internal ballistics.
A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a muzzle device that suppresses the blast created when a gun is discharged, thereby reducing the acoustic intensity of the muzzle report and jump, by modulating the speed and pressure of the propellant gas released from the muzzle. Like other muzzle devices, a silencer can be a detachable accessory mounted to the muzzle, or an integral part of the barrel.
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