Low velocity (<2,000 ft/sec): This includes all handguns.

High velocity (>2,000 ft/sec): This includes all military rifles and most hunting rifles.

Shotgun wounding potential is dependent on:

1. Chote (shot pattern)

2. Load (size of the individual pellet)

3. Distance from the target

The kinetic energy (KE) of any moving object is directly proportional to its mass (m) and the square of its velocity (v²) and is defined by the equation: (KE =½mv²)

The energy delivered by a missile to a target is dependent on:

1. The energy of the missile on impact (striking energy)

2. The energy of the missile on exiting the tissue (exit energy)

3. The behavior of the missile while traversing the target: tumbling, deformation, fragmentation

The wounding potential of a bullet depends on the missile parameters, including caliber, mass, velocity, range, composition, and design, as well as those of the target tissue.

The degree of injury created by the missile is generally dependent on the specific gravity of the traversed tissue: higher specific gravity = greater tissue damage.

A missile projectile achieves a high kinetic energy because of its relatively high velocity. The impact area is relatively small, resulting in a small area of entry with a momentary vacuum created by the soft tissue shock wave. This can draw adjacent material, such as clothing and skin, into the wound.

The direct passage of the missile through the target tissue becomes the permanent cavity. The permanent cavity is small, and its tissues are subjected to crush (Fig. 4.1).

The temporary cavity (cone of cavitation) is the result of a stretchtype injury from the dissipation of imparted kinetic energy (i.e., shock wave). It is large and its size distinguishes high-energy from lowenergy wounds.