Muzzle velocity
With muzzle velocity is defined as the speed , the shot body (or floor; s a.. Projectile ) when leaving the muzzle of the barrel of a gun has, therefore z. B. when leaving a gun barrel or the barrel . As in physics, the initial speed (pronounced “Vau zero”) is used as a symbol .
The muzzle velocity represents the maximum velocity of a projectile. As long as the projectile is still in the barrel, it is accelerated by the pressure of the combustion gases of the propellant charge . After passing the muzzle, the bullet is generally not accelerated any further or it is continuously decelerated by the air resistance.
If the mass of the bullet is known, the muzzle energy of the bullet can also be determined.
Depending on the design, a high muzzle velocity can be used to achieve a large firing range or to improve the target ballistic effect or the penetration power of projectiles.
On the other hand, there are special subsonic ammunition with a lower muzzle velocity than the speed of sound (about 350 m / s at 20 ° C) in order to prevent the loud blast of the projectile from occurring.
In the early military technology - and accordingly also in modern fireworks pyrotechnics with ball bombs and similar effects, there also ejection speed - the muzzle velocity, however, is in the range of about 100-150 m / s (about 300-600 km / h), so in principle far Below the speed of sound: Pure black powder as a propellant with its pushing effect does not reach high projectile speeds , and therefore also does not achieve long ranges. For example, with caliber 250 mm (10 inches) in large fireworks, these are in the range of 270 meters (height of rise).
In the case of high-angle firearms , the trajectory is clearly curved (indirect shooting). This allows targets to be fought without direct visual contact. With these weapons, the muzzle velocity is chosen so that when firing at the typical deployment distance, the curvature of the flight path is appropriate for the application. The projectiles are mostly grenades , the effect of which on the target does not depend solely on their kinetic energy. The propellant charge of finished cartridged ammunition for such weapons to be either relatively weak, can be reduced whereby the mass of the gun, or it is measured in the cartridge ammunition, the amount of the propellant charge so that the muzzle velocity for the particular application is most favorable.
The muzzle velocity depends on numerous constant and variable values of the internal ballistics . The most important of these are:
- Type of weapon (loading principle) and its geometry, especially the barrel (length, caliber , number and type of trains, etc.)
- Geometry, material and mass of the projectile
- Type and amount of propellant and the nature of the cartridge case
- humidity
- Powder temperature
- Temperature of the barrel
For an overview of muzzle velocities see projectile .
See also
Web links
Individual evidence
- ↑ Stuart H. James (Ed.), Jon J. Nordby (Ed.): Forensic Science: An Introduction to Scientific and Investigative Techniques, Second Edition , CRC Press , 2005, ISBN 9780849327476 , p. 414 [1]
- ↑ Fireworks when launched. pyroweb.de » Knowledge , accessed February 5, 2016.
- ↑ This is why modern fireworks use caliber in millimeters ≈ safety distance in meters