Low velocity and high velocity wounds are quite different and need identification and appropriate management.
Low velocity projectiles simply make holes. These may be through and through, they may have a straight track, or they may have a tortuous path having been deflected by bone. The result depends largely on what the hole is through, and what the surface area of the track is, since bleeding occurs from this. Dealing with a straight track involving no major vessels or organs and with the projectile at the end or buried in the scenery is the easiest possibility.
High velocity projectiles create a shock wave which causes a cavity to form with reduced pressure, into which atmospheric pressure blows whatever is nearby - typically mud, bits of cloth and assorted bacteria - and severely damaging tissues for some distance from the track. The cavity then collapses, and can look as if it is from a low velocity round.
Considering the range from which a projectile has been fired is more forensic than relevant to treatment. At close range fragments of propellant will tattoo the skin around the entry wound, at closer range the hot gases from the muzzle will burn that area. Nowadays the quickest way to record it is probably by photography.
Shotgun projectiles produce varying effects with range, from that of a solid projectile of considerable size to the individual effects of many small shot.
Resuscitation and control of bleeding to whatever extent is needed precedes definitive treatment.
Gunshot wounds are generally not to be closed in initial treatment, high velocity ones are never to be closed initially, but cleaned, debrided and inspected again aiming for delayed primary closure.
Vascular damage requires repair, fragments of bones may be best stabilised with external fixators, surgeons of sevral sorts may need to work together on a single casualty.
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