The wounding potential of assault rifles: analysis of the dimensions of entrance and exit wounds and comparison with conventional handguns. A multicentric study

The appearance of a gunshot wound (GSW) is greatly influenced by the velocity of the projectile, where high-velocity projectiles (HVPs) are defined as ballistic agents reaching a muzzle velocity of > 600 m/s fired from assault rifles. The aim of the study is to present and explain the differences in the dimensions of entrance and exit wounds between the most used handguns and assault rifles and to propose a predictor of HVP, i.e., the ratio of exit and entrance wounds (EX/ENR). The surface area of entrance and exit GSWs and the EX/ENR were calculated. 66 perforating GSWs produced by NATO FMJ 7.62 x 52 mm and 5.56 x 42 mm fired from assault rifles were assigned to the HVP, while 64 lesions produced by conventional projectiles fired from revolvers and semi-automatic pistols were assigned to the low-velocity projectile (LVP) group. The dimensions of the exit wounds of the HVP group were significantly higher when compared to the LVP group (95% CI 0.9886-2.423, p < 0.05). The HVP group showed significantly higher values for the EX/ENR when compared to the LVP group (95% CI 2.617-7.173, p < 0.05). The evaluation of the EX/ENR can be considered an adequate tool to assess the type of weapon involved and to roughly estimate the associated wounding mechanisms, which can guide both the physician in the management and treatment of the patients affected by GSW, and the forensic pathologist in crime investigation.