Muzzle Velocity

Muzzle velocity is the speed a projectile has at the moment it leaves the muzzle of the gun. Muzzle velocities range from approximately 400 ft/s (120 m/s) to 1,200 ft/s (370 m/s) in black powder muskets, to more than 4,000 ft/s (1,200 m/s) in modern rifles with high-performance cartridges such as the .220 Swift and .204 Ruger, all the way to 5,700 ft/s (1,700 m/s) for tank guns firing kinetic energy penetrator ammunition. The velocity of a projectile is highest at the muzzle and drops off steadily because of air resistance.

In conventional guns, muzzle velocity is determined by the quality (burn speed, expansion) and quantity of the propellant, the mass of the projectile, and the length of the barrel. A slower burning propellant needs a longer barrel to burn completely, but can on the other hand use a heavier projectile. A faster burning propellant may accelerate a lighter projectile to higher speeds if the same amount of propellant is used. In a gun, the pressure resulting from the combustion process is a limiting factor on projectile velocity. A balance between propellant quality and quantity, projectile mass and barrel length must be found if both safety and optimal performance is to be achieved.

Longer barrels give the propellant force more time to work on propelling the bullet. For this reason longer barrels generally provide higher velocities, everything else being equal. As the bullet moves down the bore, however, the propellant's gas pressure behind it diminishes. Given a long enough barrel, there would eventually be a point at which friction between the bullet and the barrel, and air resistance, would equal the force of the gas pressure behind it, and from that point, the velocity of the bullet would decrease.

Large naval guns will have length to diameter ratios of 38:1 to 50:1. This length ratio maximizes the projectile velocity. There is much interest in modernizing naval weaponry by using electrically driven railguns, which overcome the limitations noted above. With railguns, a constant acceleration is provided along the entire length of the device, greatly increasing the muzzle velocity. There is also a significant advantage in not having to carry explosive propellant and even the projectile internal charges may be eliminated due to the high velocity - the projectile becomes a strictly kinetic weapon.

Other articles related to "muzzle velocity, muzzle, velocity":

South Dakota Class Battleship (1939) - Specifications - Armament - Secondary Battery
... Both full charges provided a muzzle velocity of 2,600 ft/s (790 m/s) in new guns, but as continued fire wore down the barrels, muzzle velocity degraded ... The reduced charge's muzzle velocity was correspondingly lower, at 1,200 ft/s (370 m/s) ...
Air Gun Laws - Canada
... Air guns with both a muzzle velocity greater than 152.4 meters per second (500 feet per second) and a muzzle energy greater than 5.7 joules (4.2 foot-pounds) are ... Usually the manufacturer’s specifications are used to determine the design muzzle velocity and energy ... Air rifles that meet these velocity and energy criteria are classified as non-restricted firearms, while air pistols are classified as restricted if their barrel is longer than ...
Littorio Class Battleship - Design - Armament
... These long-barrel, high-velocity guns were chosen to compensate for the smaller 381 mm shell as compared to the 406 mm gun originally desired ... The guns fired a 885 kg (1,950 lb) armor-piercing (AP) shell at a muzzle velocity of 870 meters per second (2,900 ft/s) ... The high muzzle velocity of the guns reduced their service life and increased the dispersion of the fall of shot ...
B-10 Recoilless Rifle - Ammunition
... BK-881 - HEAT-FS 3.87 kg. 0.46 kg of RDX ...

Famous quotes containing the word muzzle:

    You shall not muzzle an ox while it is treading out the grain.
    Bible: Hebrew, Deuteronomy 25:4.