Kinetic Energy
Definition
KE = (1/2) m v squared, where m is projectile mass and v is velocity. Doubling velocity quadruples the kinetic energy delivered on target. Reported in joules.
- Formula
- KE = 1/2 m v squared
- Unit
- Joules
- Velocity effect
- Doubling velocity quadruples kinetic energy
- Application
- Wound severity and penetration estimation
Common questions
Why does velocity affect terminal ballistics more than bullet mass does?+
Because kinetic energy scales with the square of velocity but only linearly with mass, a modest increase in muzzle velocity delivers a much larger jump in energy on target than an equivalent percentage increase in bullet weight, which is why velocity is emphasised when comparing wounding potential.
Does kinetic energy at the muzzle equal the energy delivered to the target?+
No. Energy is lost to air resistance over the bullet's flight path and further lost to any intermediate barrier it passes through, so the energy actually delivered on impact is calculated from the striking velocity at that specific range, not the muzzle value.
Related terms
- Accidental Discharge
- Unintended firing of a weapon without a deliberate trigger pull, usually caused by mechanical defect, sear wear, drop impact or unsafe handling.
- Choke (Shotgun)
- Constriction at the muzzle of a shotgun barrel that controls pellet spread. From most-open to most-tight: cylinder, improved cylinder, modified, full choke.
- MOA (Minute of Angle)
- 1/60 of a degree of arc. Equal to approximately 2.908 cm (1.047 inches) at 100 m. Used in civilian and some law...
- Muzzle Velocity
- Speed of the projectile at the instant it leaves the barrel, expressed in metres per second (m/s) or feet per second (fps)....
- Ordnance Gelatin
- Calibrated tissue simulant. 10 per cent gelatin at 4 degrees C is the NATO and FBI standard; 20 per cent gelatin is...
- Permanent Cavity
- The lasting wound channel produced by the bullet's direct crushing and laceration of tissue. Diameter approximates expanded projectile diameter. At handgun velocities,...
- Ricochet
- The deflection of a bullet off a surface at a low angle of incidence, producing a new trajectory that diverges from the...
- Temporary Cavity
- The transient radial tissue displacement produced by a bullet's passing. Caused by the transfer of kinetic energy to surrounding tissue via compression...