Police officers, members of the military and federal agents all wear bulletproof vests in certain situations. Most bulletproof vests are not 100 percent bulletproof, but do a very good job of stopping most bullets from penetrating the vest and injuring the person wearing it. However, despite the excellent protection offered by vests, people are still injured while wearing them.
Why Injuries Occur
Bulletproof vests aren't, in fact, completely bulletproof. Instead, they work by rapidly dissipating the energy from the bullet. That energy still has to go somewhere, and it can cause injuries to the person wearing the vest. However, the dissipation of energy prevents the bullet from penetrating into the target with lethal force. This is possible due to the way that Kevlar fibers are bound together. The tiny fibers are very difficult to stretch. The fibers absorb most of the force from the bullet that would otherwise travel directly into the target.
The first effect of being shot while wearing a vest is going to be a strong rearwards force that can knock the person receiving the shot off his feet. Even though the force is dissipated, it is still an incredibly high-velocity force essentially hitting a person square in the chest. The amount of force depends on a number of factors, such as the distance from which the person was shot, the caliber of the weapon and the type of ammunition used.
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Minor to Moderate Injuries
Minor injuries result from the remainder of the force from the initial shot. If a vest is rated to the type of bullet being fired at it, 85 percent of people shot in the vest area receive minor or no injuries, according to a report complied by the Akron police department and Akron General Medical Center. Minor wounds include bruising and slight damage to the skin's surface. Moderate injuries occur sometimes even in people wearing properly rated vests, and may include cracked ribs.
Major injuries result usually when the person shot in the vest is shot with a bullet that is much stronger than those the vest is designed to protect against. Most vests are designed to protect against shots fired from handguns. A high-powered rifle shoots a projectile with much more force than even very large handguns. A shot from that type of gun could pierce a vest and result in a fatal wound.