Search

The one-by-one examination of the increasing Open Case File (OCF) archive by comparison macroscope has become a time-consuming process and the last quarter of the 20th century witnessed the development of automated ballistic identification systems. After the utilization of these systems, government institutes, scholars and the companies devising such systems conducted various performance tests to analyze duration and correlation. The performance of BALİSTİKA and similar automated firearms identification systems are frequently measured using the pistol cartridges. This study brings a new perspective to automated ballistic identification system performance tests through using same and different brand steel 7.62 × 39 mm cartridge cases. The performance of BALİSTİKA system was measured using 4387 comparison cartridge cases according to breech face, firing pin, ejector marks and combined evaluation criteria. It was determined that correlation performance of BALİSTİKA for the same brand cartridges are higher and ejector marks are the most distinct matching criteria for 7.62 × 39 mm steel cartridge cases. The test results are presented under the headings of weapon-manufacturer countries, automated ballistic identification system matching criteria for both same and different cartridge brands. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Blank cartridge actuated dummy launching devices are used by migratory bird hunters to train dogs to retrieve downed birds. The devices create a loud noise while simultaneously propelling a hard foam dummy for retrieval. A newly developed dummy launcher is based on a modified cal. 9mm P.A. blank handgun with an extension tube pinned and welded to the barrel imitation. Currently, there are no experimental investigations on the ballistic background and trauma potential of these uncommon shooting devices. Methods: An experimental test set-up consisting of a photoelectric infrared light barrier was used for measurement of the velocity of hard foam dummies propelled with an automatic dummy launcher. Ballistic parameters of the dummies and an aluminium sleeve as improvised projectile (kinetic energy (E), impulse (p), energy density (E′) and threshold velocity () to cause penetrating wounds as a function of cross-sectional density (S)) were calculated. Results: The average velocity () of the dummies was measured 25.71m/s exerting an average impulse (p) of 3.342Ns. The average kinetic energy (E) was calculated 43.04J with an average energy density (E′) of 0.069J/mm2. The average velocity () of the aluminium sleeves as improvised projectiles was measured 79.58m/s exerting an average impulse (p) of 2.228Ns. The average kinetic energy (E) of the aluminium sleeves was calculated as 88.70J with an average energy density (E′) of 0.282J/mm2. Conclusion: The energy delivered by these shooting devices is high enough to cause relevant injuries. The absence of skin penetration must not mislead the emergency physician or forensic expert into neglecting the potential damage from these devices. [Copyright &y& Elsevier]

Abstract: Introduction: Cal. 9mm×17mm industrial blank cartridges deserve special interest in the field of forensic ballistic. This calibre is most often used in Kerner-type livestock stunners, but also in different power tools. The legal framework of these industrial blank cartridges is provided by the C.I.P. and DIN 7260 regulations. The aim of this investigation is to describe and compare two experimental test procedures for measurement of maximum gas pressure and kinetic energy of cal. 9mm×17mm industrial blank cartridges according to standardized C.I.P. and DIN 7260 protocols and to provide these ballistic data. Methods: Using two different pressure measurement barrels and standardized test projectiles, the maximum gas pressure and the kinetic energy of the test projectiles are investigated. While the pressure take-off point in C.I.P. protocol is at the cartridge mouth, the DIN 7260 protocol is modified using a pressure take-off point in the cartridge chamber. For each test protocol (C.I.P. and DIN), maximum gas pressure, velocity, impulse and energy of the test projectiles are measured. Each ten cartridges from the same ammunition lot of four different energy levels (red, blue, yellow, green) are investigated. Results: While the cartridge energy values are comparable between the two different test protocols, maximum gas pressure measured in the DIN set-up (3907bar) far surpasses the gas pressure in the C.I.P. protocol (1586bar). Both test protocols observed higher energy values of the green and yellow cartridges than regulated in DIN 7260. Conclusion: Enormous gas pressure values of more than 3900bar emphasize the power of industrial blank cartridges. Once again, the harmlessness of these blank cartridges and the weapons/tools that are operated with these propellants is refuted. [Copyright &y& Elsevier]

Abstract: Introduction: 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. Methods: 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. Results: The maximum gas pressure in the explosion chamber was up to 1100bar. The shot development over time showed a typical gas pressure curve. Flow velocity of the gas jet was up to 2000m/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 11,500N 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. Conclusion: 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. [Copyright &y& Elsevier]

Evaluation of cartridge cases is essential within forensic ballistic analysis and is used in an attempt to establish a connection to the weapon used to fire it. This study consists of two experiments. The aims of Experiment 1 were to establish whether micro-CT is appropriate and repeatable for ballistic cartridge case analysis and if measurements can be extracted repeatably and reliably. Experiment 2 aimed to compare cartridge cases from two weapons to establish the magnitude of variation within and between weapons. A total of 48 cartridge cases fired by two distinct weapons were collected and micro-CT scanned to a high resolution. One randomly selected cartridge was scanned ten times under the same conditions to ensure repeatability of the scanning conditions in Experiment 1. Three novel measurements to quantitatively assess the firing pin impressions were proposed in Experiment 1 and comparatively analysed from two weapons in Experiment 2. Experiment 1 showed that micro-CT is an effective and highly repeatable and reliable method for 3-dimensional imaging and measurement of ballistic cartridge cases. Furthermore, high agreement for inter-rater reliability was found between five raters. Quantitative micro-CT analysis of the firing pin impression measurements in Experiment 2 showed a significant difference between the two studied weapons using Welch's t-test (p < 0.01). This study shows the advantage and reliability of utilising micro-CT for firing pin impression analysis. Quantitation of the firing pin impression allows distinction between the weapons studied. With expansion to further weapons, application of this methodology could complement current analysis techniques through classification models. [ABSTRACT FROM AUTHOR]