Murder Call

Ballistics is the science of the motion of projectiles. It is divided into interior ballistics, external ballistics, and terminal ballistics. Interior ballistics is the study of the projectile in the gun; exterior ballistics, the study of the projectile through air; and terminal ballistics, the study of penetration of solids by the missile. Wound ballistics can be considered a subdivision of terminal ballistics concerned with the motions and effects of the projectile in tissue. A moving projectile, by virtue of its movement, possesses kinetic energy. For a bullet, this energy is determined by its weight and velocity:   K.E. = WV2/2 g Where g is gravitational acceleration,W is the weight of the bullet, and V is the velocity. Velocity plays a greater role in determining the amount of kinetic energy possessed by a bullet than does weight. Doubling the weight doubles the kinetic energy, but doubling the velocity quadruples the kinetic energy. The concept of a gunshot wound...

Rifles and handguns have rifled barrels, that is, spiral grooves have been cut the length of the interior or bore of the barrel. Rifling consists of these grooves and the metal left between the grooves—the lands. The purpose of rifling is to impart a rotational spin to the bullet along its longitudinal axis. This gyroscopic effect stabilizes the bullet’s flight through the air, preventing it from tumbling end over end. This spin does not, however, stabilize the bullet after it enters the body due to the greater density of tissue compared to air. The term “twist,” as it pertains to rifling, refers to the number of inches or centimeters of bore required for one complete rifling spiral. All modern weapons have a twist which is constant for the entire length of the barrel. Some weapons manufactured in the beginning of the 20th century, had a “gain” twist; in this type of rifling, the rate of twist increases from breech to muzzle. Muzzle velocity is allegedly increased 5 to 6%....