Search

In examining deaths resulting from gunshot wounds, it is important to describe the wound pathway created by the projectile. Forensic pathologists must identify all entrance and exit wounds and account for all projectiles. Occasionally, confusion arises as to whether a skin defect represents an entrance wound or not, an exit wound, or some other type of wound. Herein, we propose the descriptor "bullet track skin defect" as a formal description for a superficial skin defect created along the pathway of a projectile within the body. Specifically, we define the "bullet track skin defect" as a partial‐ or full‐thickness skin defect produced by a projectile traveling beneath the skin in a relatively tangential fashion as part of a wound pathway within the body. It is somewhat analogous to a traditional graze or superficial tangential wound, wherein the projectile traveling outside the body strikes the skin tangentially from above, without entering the body. However, the projectile is already traveling within the body with the bullet track skin defect, disrupting the skin tangentially from below rather than from above, without exiting the body. Although these defects are not a common presentation of gunshot wounds, they are certainly not rare. With this case series, we suggest that such defects may be referred to as "bullet track skin defects." Alternative language that can substitute for "bullet track skin defects" includes "bullet track skin wounds" or "bullet track cutaneous defects." [ABSTRACT FROM AUTHOR]

The balancing force of the interior ballistics is an important issue in the design of the recoilless gun. It has been found in practice that the balancing force design method for recoilless guns based on the traditional classical interior ballistic theory cannot guide the balance from the physical mechanism and process. In order to study the unbalanced force experienced by the recoilless gun during the firing of the projectile and the variation law of its various parameters with time, the analysis and calculation method of the balanced interior ballistics is proposed in this article. This method separately models the aerodynamic and propellant combustion processes of the recoilless gun, using the characteristic line method to solve the model numerically. This method can be used to predict the change of the unbalanced force acting on the recoilless gun during the projectile firing of the recoilless gun. The reliability of the algorithm is verified by the interior ballistic performance when China 78 type 82 mm recoilless smoothbore gun launches the projectile. The study found that the unbalance impulse generated by the gas inside the barrel fired by the recoilless gun accounts for only 1.5 % of the total recoil impulse, but it has a great influence on the amount of impulse a shooter has can take. This approach provides a better understanding of this complex internal ballistic process, which has important implications for the design and improvements of recoilless guns. [ABSTRACT FROM AUTHOR]

Soot is deposited from 20–30 cm from the muzzle of most handguns and arranged concentrically around the entry wound. We examined a case of a self‐inflicted gunshot wound from a 9‐mm pistol that left an unusual pattern of soot deposition consisting of two circular 3‐mm deposits of soot located 2 cm from the entry wound. Examination of the weapon and test‐firing it against a cloth reproduced the soot deposits, which were caused by two ports on the top of the barrel. Examination of the weapon and comparing the barrel with the entry wound and surrounding skin may provide important information about the type of weapon, the muzzle‐to‐target distance, and atypical soot deposits. [ABSTRACT FROM AUTHOR]

Rarefaction wave gun can significantly reduce the recoil and the barrel heat without affecting projectile velocity during the launching process. This paper aims to improve the understanding of the muzzle flow characteristics during a rarefaction wave gun firing and clarify the different ballistic behaviors between the rarefaction wave gun and the traditional gun. First, the mathematical models and the numerical methods of the muzzle flow with the interior ballistic process were established. Then, the numerical simulation results were compared with the experimental data to validate the reliability and accuracy. Next, the rarefaction wave propagation behavior was described, and the interior ballistic process of the rarefaction wave gun was compared with that of the traditional gun. Then the development law of the muzzle flow field for the rarefaction wave gun coupled with the interior ballistics process was studied. Finally, the different detailed results of the muzzle flow between the traditional gun and the rarefaction wave gun were investigated. The development processes of the muzzle flow in both guns are generally similar, but the strength of the main flow parameters and the ballistic performances for the rarefaction wave gun are smaller than that for the traditional gun due to the rarefaction wave influence. This paper could provide a valuable reference for the research and design on the rarefaction wave gun. [ABSTRACT FROM AUTHOR]

Assessment of wound characteristics and the identification of various constituents of firearm discharge at autopsy play a key role in the determination of range of fire. In relation to wounds caused by shotguns, identification of the wad within the wound track, or of injury caused by the wad, is typically thought to suggest a fairly close range of fire. We present a case of a fatality due to a shotgun slug wound where the presence of the wad within the decedent's body was proposed by defense at criminal trial to favor accidental close range discharge during a struggle for the weapon—as opposed to the prosecution's contention of intentional firing of the weapon from a greater range and through an intermediate target. We undertook test firing of a shotgun of similar design to that which was fired during the interaction (a 12‐gauge pump‐action shotgun) using shotshells consistent with the slug that was recovered from the body (Winchester Super X brand), which demonstrated that the non‐attached fiber wad present in this shotshell design can accompany the slug over distances of at least up to 22 feet (6.7 m) and even after transit through intermediate targets such as a vehicle headrest. These novel data provide assistance with estimation of range of fire in instances of injuries caused by shotgun slugs. [ABSTRACT FROM AUTHOR]

Ammunition designers are faced now a day with the tasks of improving muzzle velocity (MV) to achieve required penetration as well as developing gun propellant with minimum variation of ballistics at extremes of temperatures so as to maintain safe chamber pressure of gun. In order to meet the requirement an optimized propellant composition containing RDX, energetic plasticizer, nitrocellulose (NC), cellulose acetate (CA) and additives referred as Enhanced Energy Propellant (EEP) was processed and evaluated theoretically and experimentally. Performance in respect of ballistic parameters (static and dynamic), sensitivity, thermal characteristics, thermal stability and mechanical properties were evaluated and compared with that of the conventional triple base propellant (TBP). Experimental data on comparative study indicated that the newly developed EEP is superior to existing TBP in terms of energy, stability and thermal properties while sustaining the safe chamber pressure of gun. Dynamic firing results show that, EEP requires lower charge mass (7.43 kg) and lesser chamber pressure (459 MPa) to realize MV at par with standard. This illustrates high energy of EEP. [ABSTRACT FROM AUTHOR]

Factors influencing effectiveness of automated comparisons, test‐fired bullets, and cartridge cases from 0.38 Special revolvers were logged into the Evofinder® Ballistic ID System. Tests were performed as follows: First test correlated test‐fires of the same type, second test compared different types of ammunition components, third test replicated the second test in a larger database, and fourth test replicated the third test with students having no previous firearm identification experience. System effectiveness with projectiles in the first test was 0.89. With cartridge cases, effectiveness was 0.79 with combined results, but analysis of separate results by breech face and firing pin revealed low effectiveness by breech face (0.40). In the second, third, and fourth tests, effectiveness with projectiles were 0.61, 0.51, and 0.44. In addition, these tests had effectiveness with cartridge cases equivalent to 0.55, 0.43, and 0.44. Results are useful to establish routine protocols, system improvements, or comparative assessment of other electronic systems. [ABSTRACT FROM AUTHOR]

A review of the literature concerning the fate and behavior of gunshot residue ( GSR) is presented. A number of concomitant parameters including firearm and ammunition type, plume and GSR material characteristics, travel distances, chemical composition and GSR morphology are critically discussed in relation to their effects on the distribution and deposition, transfer and persistence processes of GSR. The underlying mechanisms associated with such processes are also considered. Knowledge of these processes on GSR materials could provide valuable information concerning scene preservation and subsequent forensic sampling. The number of GSR particles deposited can vary significantly with each firearm discharge, highlighting the potential to produce distinctive data in each individual case. With the continual development and compositional changes of new ammunition types, further evaluation of the effect these processes may have on GSR evidence and their possible influence on the interpretation of the analytical results should be given due consideration. [ABSTRACT FROM AUTHOR]

Historically, in crimes involving heavy caliber rifles, only conventional factory-made versions have been used. However, in recent years the number of homemade long-barreled rifles is increasing. The characteristics of two such firearms that have been submitted to the Turkish Criminal Laboratory are discussed here. When the main parts of the guns were examined in detail, it was noted that nearly all of the parts had been made carelessly, with several structural defects visible. It was determined that the homemade heavy caliber rifles were unfit for efficient use and it was possible that they could have seriously harmed the shooter had they been fired. The development of these kinds of gun and the possibility of their use spreading throughout the country in terrorist attacks could cause a serious threat to national security. [ABSTRACT FROM AUTHOR]