Wounding effects of two types of bullets on soft tissue of dogs

The wounding effects of 5.56 and 7.62 mm calibre bullets, hitting on soft tissues of 130 dogs at various velocities ranging from 513 to 933 m/s have been studied. The injury caused by 5.56 mm bullet was more severe than that caused by 7.62 mm bullet. This is due to the difference in ballistic behavior between the two types of bullets. The wound caused by 5.56 mm bullet was characterized by a trumpet-shaped channel with large defect. The skin around the exit was torn away and its shape was irregular, which, however, occurred only when the tumbling and the breaking of the bullet existed. High-speed X-ray photograph demonstrated that in 5.56 mm bullet group, temporary cavity was much larger and lasted longer. Splashing phenomenon could be seen at the exist and the fragments of the bullet could be found somewhere. Based on the comparisons the amount of absorbed energy, the volume of wound channel, the frequency of developing complex wound and the ratio of dimensions between the entrance and the exit, it proved that the injury caused by 5.56 mm bullet was several to dozens of time as severe as that caused by 7.62 mm bullet. Nevertheless, wound extents by both types of bullet would be similar if the inflicting bullet did not show any significant tumbling, breaking or deformation.