The use of computered tomography (CT) to investigate damage caused by air rifle pellets

Research in firearms requires specialised facilities and extensive studies have been carried out by manufacturers and law enforcement agencies. However, considerably less work has been performed on air weapons, even though there are fatalities in the UK from these legally held weapons. Computed tomography scanning (CT scanning) is widely used in medical applications to 'see' inside the human body. A series of 2D radiographic projections are taken and reconstructed into a 3D volume that can be rotated and examined with micron-scale accuracy. The technique has undergone rapid expansion in its application in research fields as diverse as soil physics & chemistry, and material science where the ability to ‘virtually dissect’ opaque components has leant itself to the development of methods for the quantification of internal structures. In the present study CT scanning has been used to investigate tissue damage caused by air rifle pellets under laboratory conditions. Employed extensively to simulate human flesh, ballistic gel has been used to investigate the behaviour of air rifle pellets following impact with flesh. The second phase of this work has looked at the impact of pellets on bone embedded in ballistic gel to examine both the damage caused to the bone, and to the pellet. VGStudioMax software (Volume Graphics GmbH, Heidelberg, Germany) enables the virtual extraction and property analyses of each part of the model including wound tract, surrounding tissue damage and pellet deformation upon impact; all without any destruction of the original sample.