Gunshot wounds caused by smooth-bore firearms (shotguns)

Gunshot wounds caused by smooth-bore firearms (shotguns)

These wounds merit a separate discussion because shotguns and their ammunition differ so markedly from rifled weapons and their ammunition. As mentioned above, range, gauge (barrel diameter), degree of ``choke'' and size and number of pellets in the shell play a role in determining the characteristics of shotgun injuries. The explosive effect and the burns created by the muzzle flame can cause additional damage to the damage created by the shot if gun and victim are sufficiently close. Additional trauma may result from the wadding striking the victim, a feature not seen in other types of firearm injuries.

Contact and close-range cutaneous shotgun entrance wounds are round or elliptical, depending on the angle between muzzle and skin. Smoke and powder residue with scorching, surround the entrance wound, and marginal abrasion similar to a single-bullet entrance is present. Occasionally, stellate lacerations due to the muzzle blast are seen as gases expand beneath the skin and lacerate the wound edges as they exit through the original entrance. Contact shotgun wounds of the head commonly cause extreme mutilation.

With close-range shots of up to 120 to 150 mm the shotgun charge enters the body as a single conglomerate mass producing a round defect somewhat larger in diameter than the bore of the barrel. Wound margins in such cases show abrasion as well as scalloped defects. The linear abrasions occasionally seen in the immediate vicinity of these wounds are due to the impact of clothing against the stretched skin during penetration of the shot.

Beyond this range, as muzzle-to-target distance increases, the major central defect becomes progressively smaller and individual pellet wounds become more numerous as the pellets begin to fan out. However, the minimal distance at which this occurs varies considerably, ranging from 90 to 120 mm with sawn-off shotguns, 180 mm with cylinder-bore guns and up to 540 mm with full-choke guns. Wadding and plastic casing usually enter the wound when muzzle-to-victim distance is less than 150 to 180 mm.

As a rough estimate it is usually accepted that for every meter the pellets will disperse 2,5 to 3,0 cm. If the diameter of the wound (the maximum distance between the most remote pellet wounds on the skin) is therefore 30 cm, the firing distance was approximately 10 meters.