Analysis of gunshot injuries to the different surfaces of the shaft of a porcine femur with various lead airgun pellets fired from a 6.35 mm calibre air rifle using a human thigh model

Abstract

Modern air weapons are approaching firearms with their capabilities. Shots from this type of weapon pose an increasing threat to humans and animals. The vast variation in airgun ammunition means that gunshot damage can vary depending on the type of bullet that hits the tissues. The study was undertaken to investigate how the type of lead airgun pellet calibre of 6.35 mm and surface of femoral shaft affected by gunshot damage have impact on extent of bone and periosteal entry damage. In our study, we subjected a porcine femur contained in a ballistic gelatine human thigh model to damage. 3 types of Haendler&Natterman (H&N) airgun pellets were fired at the anterior, posterior and lateral surfaces of the femoral shaft. The impact energies of the projectiles were measured. The properties of the femoral shaft were evaluated. The models were then subjected to X-ray imaging and slicing for photographic evaluation of pellet shot damage. The surface area of inlet damage in the bone and periosteum was measured, and the ratio of these dimensions to each other was calculated. It was noted that the posterior wall of the porcine femoral shaft is the thickest, and the lateral wall has the greatest variation in thickness. As a result of statistical analysis, it was noted that for the front surface of the femoral shaft, H&N Baracuda Hunter shot generated the biggest damage area and H&N Silverpoint the smallest; for the posterior surface, H&N Baracuda Hunter biggest and H&N Baracuda smallest damage area respectively; and for the lateral surface, H&N Silverpoint the biggest and H&N Baracuda the smallest damage area respectively. This is most likely influenced by the properties of the individual airgun pellets and the different thicknesses of the femoral shaft walls, including significant variation in the thickness of the lateral wall.