Determination of impact parameters and efficiency of 6.8/15 caliber captive bolt guns.

While the morphological appearance of injuries due to powder-actuated captive bolt stunners has been extensively investigated, medicolegal literature contains, except for one work by Nadjem and Pollak (Arch Kriminol 203:91-102), no further investigations into the physical impact characteristics of these sharp-edged circular punching tools. However, basic physical parameters, such as bolt velocity, momentum, kinetic energy, and energy density, play a crucial role in the medicolegal and traumatological assessment of captive bolt stunners and the related injuries. And also, regulatory bodies demand a reliable and repeatable measurement test set-up for the determination of captive bolt stunners' impact characteristics. Therefore, it is the aim of this work to design and describe a test set-up based on one single photoelectric light barrier and to determine the impact parameters for a series of newly developed cal. 6.8/15 stunning devices. We found that bolt velocity ranges from v = 42 to 54 m/s, while momentum ranges from p = 11 to 14 Ns, and kinetic energy reaches values from E = 224 to 369 J. The efficiency of the captive bolt stunner, defined as the ratio of the kinetic energy of the stunner's bolt to the potential energy of industrial blank cartridges, also described in this work for the first time, was found to vary between 36 and 46 %.