Surviving a Gunshot Wound to the Head
Most people learn about gunshot wounds from watching television or going to the movies. From Gunsmoke to the Sopranos, and action packed films, guns and violence are often integral parts of the story line. Being shot on the screen can result in instant death, drawn out death scenes, or heroes who brush off the injury and save the day. In real life, the same alternatives exist, depending upon what type of firearm and bullets were used, and where the bullet(s) entered and/or exited the body. It's all a matter of physics and how much damage the energy the bullet causes.
When a bullet hits the body, all the energy it has is transferred to the body tissue causing damage. The heavier the bullet and the faster it moves the more damage it can potentially cause. The laws of physics state that energy is directly related to the weight of the bullet, meaning that if the weight doubles, the energy doubles. But energy increases by the square of the velocity. Doubling the speed increases the energy fourfold. The purpose of a gun is to make a bullet go faster.
The type of bullet can also make a difference. If it is narrow and maintains its shape when it hits the body, it may be able to pass right through tissue without causing much secondary damage. However, if it's built to explode on contact, more tissue injury may occur. The way the bullet hits and enters the body is also important and has to do with the yaw, or side to side movement of the bullet as it enters the body. An analogy is a football thrown in a tight spiral, there is less resistance as it passes through the air than if it is moving side to side or wobbling. The more the wobble, the greater the potential to transfer energy to the body and cause damage.