Edge, size and temperature effects in soft soap block simulant targets used for wound ballistic studies

In order to investigate the influence of various parameters on the outcome of wound ballistic tests using soft soap tissue simulant targets, an experiment study was performed. 6 mm spherical steel-balls were fired from a 6 mm smooth-bore rifle, giving a maximum velocity of about 1500 m/s. Such factors as the geometry of the target (square or cylindrical), location of the hit (eccentricity), size, temperature (0-20 degrees C) and method of evaluation were varied in a systematical manner. The results of the study indicate the accuracy to be expected in performing such tests, the limits within which variation may be allowed to ensure valid results. Finally a model for calculating the retardation force on the projectile as a function of penetration depth (energy transfer characteristics) from measurements of the diameter of the permanent cavity in the block is described, with block size and temperature as parameters. It must be emphasized that the results are valid only for the specific material studied. The results, however, make it likely that there exists a relatively simple method of calibration that can be applied to determine the specific values of parameters for other similar materials.