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Abstract
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Cranial gravitational bullet injuries and human and material losses apply to those falling bullets and their effect when they struck the cranium of human being and their consequence and material loss. Our aims were to study the importance of craniocerebral falling-bullet injuries, the clinical and computed tomography scan criteria, events that are associated with bullet firing, treatment options, and outcome of these injuries. Reviewing literatures: we search all the available literature from 1990 to October 2017 in PubMed, Google Scholar, and ResearchGate with the following key words: gravitational bullets injury, tangential wound, penetrating wound, ricochet, careening, and falling-bullet hear injury. The wounds caused by gravitational projectiles are a relevant problem in many countries of the world. The problem caused by this type of elements must be addressed from the prevention.
Falling bullets or gravitational bullets are the ones that move under the effect of the gravity force after the muzzle force diminished. Falling bullets are seen in aerial firing or what is classified by the international disease classification system as celebratory firing[1] during which bullets are shot into the sky to celebrate a happy event or to express anger in some countries of the middle east, north Africa, south America, and middle of Asia. Marriage ceremony is the most common event where aerial firing are done and consequent injury sustained.[2] Falling bullets are also seen in the USA and reported as incidental to street violence in 59.2% of the shooting events while due to celebratory firing in 4.6%.[3] Another event where falling bullets are seen is aerial shooting during riot and mob control noted in the setting of conflict zones.[4]
After upward shooting, the bullets will move under the effect of explosive acceleration first; then, because of the gravity, their velocities will decelerate till reaching zero, and at this point, the movement of the bullets will change to downward and their velocities will be accelerated by the effect of the gravity until the air resistance drag equalizes the effect of the gravity so the bullets will reach the terminal constant velocity.[5]
The terminal velocity of a bullet depends on multiple factors. One of them is the bullet composition. Most of the bullets are made of lead due to having a high specific gravity and more weight per volume. This will make the lead bullets have less air drag per mass when falling down which will make the terminal velocity higher.[6] Another factor that affects the terminal velocity is the angle of firing. If the angle was between 20° and 45° or even more acute, the bullet will travel further with higher speed over terminal velocity[5] while the vertical firing will end with lower terminal velocities. Other factors that determine the terminal velocities are the shape and caliber of the bullets, the direction of the bullets during the movement, and the flight characteristics, such as yaw, precession, tumbling, and nutation.
Keywords: Celebratory gunfire
Language: en |