Muzzle velocity

The muzzle velocity is the velocity of a bullet (or projectile) when it leaves the muzzle of the barrel of a weapon, e.g. when it leaves the barrel of a rifle or the barrel of a cannon. As a formula character, as in physics, for the initial velocity (pronounced "vau zero") is commonly used.

The muzzle velocity represents the maximum speed of a projectile (if it has no additional propulsion, see Sturmpanzer VI). 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 projectile is usually not accelerated any further or it is continuously decelerated by air resistance.
If the mass of the projectile is known, the muzzle energy of the projectile can also be determined.

Depending on the design, a high muzzle velocity can serve to achieve a long operational range or to improve the target ballistic effect or the penetrating power of projectiles.

On the other hand, there are special subsonic ammunition with a muzzle velocity lower than the speed of sound (about 350 m/s at 20 °C) in order to avoid the loud bullet bang.

In early military technology - and accordingly also in modern firework pyrotechnics for ball bombs and similar effects, there also ejection velocity - the muzzle velocity, on the other hand, is in the range of about 100-150 m/s (about 300-600 km/h), thus in principle far below the speed of sound: pure black powder as a propellant with its pushing effect does not achieve high projectile velocities, and thus also long ranges. These are, for example, with calibre 250 mm (10 inch) in large fireworks in the range of 270 metres (elevation).

The trajectory of the projectile is clearly curved (indirect firing). This allows targets to be engaged without direct line of sight. The muzzle velocity of these weapons is selected in such a way that the curvature of the trajectory is appropriate for the case of operation when firing at the typical operational distance. The projectiles are usually grenades whose effect on the target does not depend solely on their kinetic energy. The propellant charge of ready patronized ammunition for such weapons is either relatively weak, which allows the mass of the gun to be reduced, or, in the case of cartridge ammunition, the amount of propellant charge is calculated so that the muzzle velocity is most favorable for the particular case of operation.

Muzzle velocity depends on numerous constant and variable quantities of internal ballistics. Of these, the most important are:

• Design of the weapon (loading principle) and its geometry, in particular the barrel (length, calibre, number and type of rifling, etc.).
• Geometry, material and mass of the projectile
• the type and quantity 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

• Effective range (weapon)