Muzzle energy is the measurement of the kinetic energy of a bullet as it is expelled from the barrel of a firearm.
The general formula for the kinetic energy in a coherent system of units, including SI and cgs systems, and the gravitational foot-pound-second and the absolute foot-pound-second system, is:
- E = ½ m·v2
In SI, mass m is in kilograms and velocity v is in meters per second, giving kinetic energy in joules.
For other units, a conversion factor must be added. For example, to get muzzle energy where
- E is the muzzle energy of bullet (in foot-pounds force)
- v is the velocity of bullet (in feet per second )
- m is the mass of bullet (in grains)
The formula is
- E = m·v2/450437
Typical muzzle energy levels of different types of firearms are:
| Firearm | Caliber | Muzzle Energy
|
| (ft·lbf) | (J)
|
| air gun | .177 | 5 | 7
|
| rifle (LR cartridge) | .22 | 100 | 135
|
| rifle | .223 | 2500 | 3400
|
| pistol (semi-auto) | 9 mm | 400 | 540
|
See Also
