Understanding Bullet Wounds: Entry vs. Exit

The Dynamics of Bullet Entry and Exit Wounds

The size of the exit hole compared to the entry hole of a bullet is influenced by several factors, including the speed, size, and construction of the bullet. When a bullet enters the body, it creates an entry wound that is often smaller and more uniform. However, the exit wound can be significantly larger and more irregular. This disparity arises due to the bullet's deformation or fragmentation upon impact, which causes it to expand and create a larger exit wound.

Many bullets are designed to maximize internal damage rather than exit the body. These bullets dump all their kinetic energy into creating a massive internal wound. When bullets do exit the body, they often drag bone fragments and create a shock wave of pressure, further enlarging the exit wound. This phenomenon can be compared to a rock hitting water, creating ripples and waves that propagate through the tissue.

Bullet Design and Its Impact on Wound Size

The design of a bullet plays a crucial role in determining whether it will exit the body and the size of the exit wound. Full metal jacket rounds, typically used by the military, are designed for p********** and are more likely to pass cleanly through the body. In contrast, partially jacketed or hollow-point rounds, commonly used by hunters, police, and civilians, are more likely to fragment and not exit the body or exit with much less energy.

Partially jacketed and hollow-point rounds are made of softer alloys like lead, whereas jacketed rounds are coated in brass or copper, making them harder and less prone to deformation. Hollow-point bullets, in particular, are designed with a cone-shaped hole that causes the soft lead to mushroom out upon impact, making the bullet physically larger on exit. This mushrooming effect increases the diameter of the bullet, leading to larger exit wounds.

The Role of Bullet Speed and Size

The speed and size of the bullet significantly affect the wound dynamics. Large bullets impact the body with enough force to create a "splash" effect, similar to a rock hitting water, leading to a temporary wound cavity. If this temporary wound cavity is larger than the body part impacted, the exit wound will be larger than the entry wound. However, most handgun bullets are too small and slow to create a large temporary wound cavity.

High-speed footage of bullets being shot into ballistic gel demonstrates the kind of damage they can do and why they leave the body with such violence. The human body is mostly water, and bullets create ripples and waves that cause damage and propagate through the tissue. By the time a bullet exits the body, it is moving slower but is moving other tissue with it, contributing to a larger exit wound.

The Phenomenon of Bullet Deformation and Fragmentation

Bullets are not perfectly solid objects and will deform upon hitting a solid object, which can cause them to tumble or fragment. The deformation and fragmentation of bullets cause more serious internal damage and create a shockwave as they pass through the body. As bullets exit the body, the tissue that was pushed through the wound channel is expelled out, enlarging the exit wound.

The phenomenon of larger exit wounds can be compared to a saw cutting through wood, where the bottom side gets splinters while the top remains smooth. When a bullet enters the body, there is a lot of support material to take the impact, but upon exit, there is nothing to support the last bit, leading to more tearing. Fragmenting bullets, rotation on impact, and different bullet heads also contribute to the size and nature of exit wounds.

Understanding the dynamics of bullet entry and exit wounds is crucial for medical professionals, law enforcement, and forensic experts. The knowledge of how different bullets behave upon impact can aid in better treatment of gunshot injuries and more accurate crime scene investigations.