Comparison of Contact Shotgun Wounds of the Head Produced by Different Gauge Shotguns

Abstract

A series of 89 contact shotgun wounds of the head were evaluated to compare the extent of wounding produced by different gauge shotguns. Twelve gauge shotguns were the most common, accounting for 69% of the cases, followed by 20 gauge (18%), .410 caliber (10%), and 16 gauge (3%). The mouth was the most common entry site, used in 62% of cases. Comparison of contact intraoral shotgun wounds revealed statistically significant differences between 12 gauge and 20 gauge wounds. Whereas the extent of internal destruction was similar with both gauges, intraoral 12 gauge shotgun wounds caused bursting of the head with lacerations of the face, forehead, and scalp in 74% of cases, while only 9% of 20 gauge wounds produced a similar extent of external disruption. The external head remained fully intact in 55% of 20 gauge intraoral wounds. To account for the threshold effect for head bursting between 20 gauge and 12 gauge shotgun blasts, commercial shotshell and reloading data were analyzed. While there was considerable overlap between the two gauges, a common 12 gauge load would generate 50% more kinetic energy and 40% greater volume of gas than a common 20 gauge load. Comparison of shotgun blasts at entry sites outside of the mouth showed similar differences. Wounds from .410 shotguns were similar to those from 20 gauge weapons, and 16 gauge shotguns produced wounds intermediate between 20 and 12 gauge.