Frank M, Philipp K P, Franke E, Frank N, Bockholdt B, Grossjohann R, Ekkernkamp A
Department of Trauma and Orthopedic Surgery, Ernst-Moritz-Arndt-University Greifswald, Sauerbruchstrasse, 17475 Greifswald, Germany.
Forensic Sci Int. 2009 Jan 10;183(1-3):54-9. doi: 10.1016/j.forsciint.2008.10.007. Epub 2008 Nov 18.
Vole captive bolt devices are powder actuated spring guns that are used as a pest control mean. After having triggered the explosion of the blank cartridge by touching a metal ring around the muzzle, the vole is killed by the massive propulsion of the gas jet. Improper use and recklessness while handling these devices may cause severe injuries with the hand of the operator at particular risk. Currently, there are no experimental investigations on the ballistic background of these devices.
An experimental test set-up was designed for measurement of the firing pressure and the dynamic force of the gas jet of a vole captive bolt device. Therefore, a vole captive bolt device was prepared with a pressure take-off channel and a piezoelectric transducer for measurement of the firing pressure. For measurement of the dynamic impact force of the gas jet an annular quartz force sensor was installed on a test bench. Each three simultaneous measurements of the cartridges' firing pressure and the dynamic force of the blast wave were taken at various distances between muzzle and load washer.
The maximum gas pressure in the explosion chamber was up to 1100 bar. The shot development over time showed a typical gas pressure curve. Flow velocity of the gas jet was up to 2000 m/s. The maximum impact force of the gas jet at the target showed a strong inverse ratio to the muzzle's distance and was up to 11,500 N for the contact shot distance. Energy density of the gas jet for the close contact shot was far beyond the energy density required for skin penetration.
The unique design features (short tube between cartridge mouth and muzzle and narrow diameter of the muzzle) of these gadgets are responsible for the high firing pressure, velocity and force of the gas jet. These findings explain the trauma mechanics of the extensive tissue damage observed in accidental shots of these devices.
田鼠栓式捕杀器是一种火药驱动的弹簧枪，用作害虫防治工具。通过触碰枪口周围的金属环触发空包弹爆炸后，田鼠会因气体射流的巨大推力而被杀死。操作这些装置时使用不当和鲁莽行事可能会导致严重伤害，操作人员的手部尤其危险。目前，尚无关于这些装置弹道背景的实验研究。
设计了一个实验测试装置，用于测量田鼠栓式捕杀器的发射压力和气体射流的动态力。为此，准备了一个带有压力引出通道和压电传感器的田鼠栓式捕杀器，用于测量发射压力。为了测量气体射流的动态冲击力，在试验台上安装了一个环形石英力传感器。在枪口与负载垫圈之间的不同距离处，对弹药筒的发射压力和爆炸波的动态力进行了三次同步测量。
爆炸室内的最大气体压力高达1100巴。随时间的射击发展显示出典型的气体压力曲线。气体射流的流速高达2000米/秒。气体射流在目标处的最大冲击力与枪口距离呈强烈反比，接触射击距离时高达11500牛。近距离接触射击时气体射流的能量密度远远超过皮肤穿透所需的能量密度。
这些装置独特的设计特点（弹药筒口与枪口之间的短管以及枪口的窄直径）导致了气体射流的高发射压力、速度和力量。这些发现解释了在这些装置意外射击中观察到的广泛组织损伤的创伤机制。
