Non-fatal gunshot wounds frequently have mild to severe long-lasting effects, typically some form of major disfigurement such as amputation because of a severe bone fracture and may cause permanent disability. A sudden blood gush may take effect immediately from a gunshot wound if a bullet directly damages larger blood vessels, especially arteries. Pathophysiology
The degree of tissue disruption caused by a projectile is related to the cavitation the projectile creates as it passes through tissue. A bullet with sufficient energy will have a cavitation effect in addition to the penetrating track injury. As the bullet passes through the tissue, initially crushing then lacerating, the space left forms a cavity; this is called the permanent cavity. Higher-velocity bullets create a pressure wave that forces the tissues away, creating not only a permanent cavity the size of the caliber of the bullet but a temporary cavity or secondary cavity, which is often many times larger than the bullet itself. The temporary cavity is the radial stretching of tissue around the bullets wound track, which momentarily leaves an empty space caused by high pressures surrounding the projectile that accelerate material away from its path. The extent of cavitation, in turn, is related to the following characteristics of the projectile:

Kinetic energy: KE = 1/2mv2 (where m is mass and v is velocity). This helps to explain why wounds produced by projectiles of higher mass and/or higher velocity produce greater tissue disruption than projectiles of lower mass and velocity. The velocity of the bullet is a more important determinant of tissue injury.
He became Americas leading authority on gunshot wounds and is credited as the United States first civilian trauma surgeon.Mid-nineteenth-century handguns such as the Colt revolvers used during the American Civil War had muzzle velocities of just 230–260 m/s and their powder and ball predecessors had velocities of 167 m/s or less. Unlike todays high-velocity bullets, nineteenth-century balls produced almost little or no cavitation and, being slower moving, they were liable to lodge in unusual locations at odds with their trajectory.Wilhelm Röntgens discovery of X-rays in 1895 led to the use of radiographs to locate bullets in wounded soldiers.Survival rates for gunshot wounds improved among US military personnel during the Korean and Vietnam Wars, due in part to helicopter evacuation, along with improvements in resuscitation and battlefield medicine. Similar improvements were seen in US trauma practices during the Iraq War. Some military trauma care practices are disseminated by citizen soldiers who return to civilian practice. One such practice is to transfer major trauma cases to an operating theater as soon as possible, to stop internal bleeding. Within the United States, the survival rate for gunshot wounds has increased, leading to apparent declines in the gun death rate in states that have stable rates of gunshot hospitalizations. Research
Research into gunshot wounds in the USA is hampered by lack of funding. Federal-funded research into firearm injury, epidemiology, violence, and prevention is minimal. See also
Blast injury, an injury that may present similar dangers to a gunshot wound.