AFTE Store - Some Tests and Observations of Forensic Interest Regarding the Exterior and Terminal Ballistics of Small Lead Shot

The majority of injuries and deaths associated with shotguns that come to the attention of crime laboratories usually involve shootings at distances from contact to perhaps 20 to 25 yards (18-23 meters) with all sizes of shot from buckshot to the smallest bird shot. Reliable, published data for exterior ballistic performance and injury potential for lead shot at greater distances such as 50 to 100 yards (46 to 91 meters) and beyond are hard to come by, particularly for the smaller shot sizes intended for small game and bird hunting. American lead shot sizes 4, 6, and 8 loaded in contemporary 12-gauge shells were selected for a series of external and terminal ballistic tests at ranges of 50, 75, and 100 yards (46, 69, and 91 meters). Muzzle velocities, times of flight (ToF) to a 100-yard (91-meter) acoustic target, and individual pellet perforation of a skin simulant (1mm thick chamois skin) mounted on a soft tissue simulant (MBM ballistic soap) were obtained for each of these shot sizes at these three distances. An effective ballistic coefficient (BC) for each of these shot sizes was derived from the muzzle velocity, the 100-yard (91-meter) ToF, and the existing meteorological conditions at the time. From the three BC values derived for the three shot sizes, the maximum ranges and associated departure angles were calculated. These calculations were followed by actual test firings in which the predicted maximum range values were achieved and were in very close agreement with the calculated values.