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The paper deals with an adaptation of the standard interior ballistics model for the case of amphibious rifle shooting ammunition under water. The adapted mathematical model was validated and experimentally verified using the 5.56 mm underwater projectile shot from the 5.56 mm amphibious rifle. The dependence of the underwater interior ballistic processes on the powder mass was investigated. The results of theoretical mathematic model solution correspond very well with experiment. The described mathematical model and the dependence of the underwater interior ballistic processes on the powder mass can be a reference for designers in the design process of the underwater ammunition or underwater rifle. [ABSTRACT FROM AUTHOR]

The analysis was performed on six commonly used 5.56 x 45 mm projectile types (M193, M855, M855A1, L31A1, M995, and AP45). The projectile's impact velocity (chosen as 900 m/s) was the same in the examination process. This made it possible to assess how the projectile's design has affected its performance against a hard steel target. These evaluations included numerical simulations (Ansys Autodyn) of projectile impacts. Using the available experimental data, the materials in the computational model were first validated. A short description and CAD model of projectiles is also given. Relevant conclusions were reported. [ABSTRACT FROM AUTHOR]

In practical forensic casework, backspatter recovered from shooters' hands can be an indicator of self-inflicted gunshot wounds to the head. In such cases, backspatter retrieved from inside the barrel indicates that the weapon found at the death scene was involved in causing the injury to the head. However, systematic research on the aspects conditioning presence, amount and specific patterns of backspatter is lacking so far. Herein, a new concept of backspatter investigation is presented, comprising staining technique, weapon and target medium: the 'triple contrast method' was developed, tested and is introduced for experimental backspatter analysis. First, mixtures of various proportions of acrylic paint for optical detection, barium sulphate for radiocontrast imaging in computed tomography and fresh human blood for PCR-based DNA profiling were generated (triple mixture) and tested for DNA quantification and short tandem repeat (STR) typing success. All tested mixtures yielded sufficient DNA that produced full STR profiles suitable for forensic identification. Then, for backspatter analysis, sealed foil bags containing the triple mixture were attached to plastic bottles filled with 10 % ballistic gelatine and covered by a 2-3-mm layer of silicone. To simulate backspatter, close contact shots were fired at these models. Endoscopy of the barrel inside revealed coloured backspatter containing typable DNA and radiographic imaging showed a contrasted bullet path in the gelatine. Cross sections of the gelatine core exhibited cracks and fissures stained by the acrylic paint facilitating wound ballistic analysis. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Mechatronics. Armament, Aviation, Safety Engineering / Problemy Mechatroniki. Uzbrojenie, lotnictwo, Inżynieria Bezpieczeństwa is the property of Index Copernicus International and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Calculating of the interior ballistics characteristics using seven-perforated nitrocellulose powder in cartridge assemblies can be used in special techniques and in special projectile sets. Accuracy of interior ballistics characteristics calculations influences construction solutions of special techniques and ammunition; main utilization is in armed forces special techniques and ammunition for country defence. Originally derived relations make geometric coefficients solution of non-treated seven-perforated powder more accurate and easier to use. [ABSTRACT FROM AUTHOR]

Projectiles in coil gun usually make one-way movement and move at a very high speed. The device would be fit for the application of oil pumping unit, as long as the projectiles can make reciprocating movement and move slower by adopting proper control methods. At present, during the production process of petroleum, the efficiency of the system is rather low. Energy dissipation takes a considerable ratio in the total cost of oil production. Moreover, beam pumping-unit system suffers from long driving chain, poor flexibility, a quite huge capacity and weight under long length of stroke, and low efficiency. Aiming at the earlier problems, linear electromagnetic oil pumping unit is presented in this paper, which is essentially a multiphase coil launcher. Analysis is made about the advantages and disadvantages of three~phase and multiphase structures, as well as the practical structure. Simulation studies are made; meanwhile, experimental investigations are carried out on a small-scale-model machine system. Further simulation studies of coil launching system are carried through the mechanical and mathematical models of rod string in a sucker-rod pumping-unit system. Theoretical analysis and experimental results verify the feasibility and the validity of the proposed system. Thus, a new path to solve the problem of high energy dissipation in oil production is explored. [ABSTRACT FROM AUTHOR]

The development of lightweight armour systems for ballistic protection is under continuing attention of the manufacturers and users. A new design of the composite armour systems has been developed and ballistically tested. A new armour system consists of a ceramic plate, an intermediate ceramic–polymer layer and a polymer fibre lining as a backing material. The proposed composite armour systems prepared with a use of specially selected compositions of the intermediate layer promoting the absorption of the kinetic energy of projectiles provide adequate ballistic protection to National Institute of Justice (NIJ) level III and level IV, and they successfully withstand multiple hits. [ABSTRACT FROM AUTHOR]

The ignition performances of percussion primers for small calibre ammunition are determined using a new experimental setup, with pressure transducers and special designed combustion chambers. The method enables a comparison of new designed primers with consecrated models by relative ignition capacity. Results show that ballistic performances of primers are in direct relationship with the gradient pressure vs. rise time and also with the maximum pressure developed inside the cartridge chamber. [ABSTRACT FROM AUTHOR]

Despite the fact that a large amount of small arms ammunition has been used up over the past two years, their stocks in warehouses and arsenals in various countries are quite large. And their shelf life is 20 years or more. In addition, over time, the number of such ammunition will increase. Among the large number of requirements for modern small arms, one can highlight the provision of the necessary survivability of its parts and mechanisms. The problem of barrel survivability is especially important. One of the factors affecting barrel survivability is changes in internal ballistics parameters. In turn, these parameters change when using ammunition whose service life exceeds the warranty. In this regard, the task of studying the survivability indicators of small arms barrels when using post-warranty ammunition seems relevant. The requirements for barrel systems and factors affecting the wear of the barrel bore of powder charges during long-term storage have been determined. An analysis of changes in the ballistic characteristics of powder charges was carried out, which allows to state increased wear of barrels when using ammunition with long storage periods. The dependencies for determining the limit number of shots from a weapon sample are analyzed. A method for predicting barrel survivability when using long-term storage ammunition is proposed. Data are presented on an experimental study to determine changes in barrel survivability as a result of the use of long-term storage ammunition by estimating changes in the initial velocity of the projectile. Based on the results obtained, ways for further research are proposed in the direction of expanding the range of ammunition and weapons. [ABSTRACT FROM AUTHOR]

This paper put forward a method of reducing the armor-piercing projectile hit probability by investigating the characteristics of modern tank fire control system and armor-piercing projectile. A hit probability model based on traditional firing theory was established and analyzed. The results show that this method is effective. The further study points out that the most effective way to decrease the hit probability is reducing the response time of the target. [ABSTRACT FROM AUTHOR]

• Small and medium arms fire can be stopped with a snow-based protective structure. • Snow-filled commercial gabions can be efficiently constructed. • Structures can be construction at a rate of about 0.5 hr/m3 with common equipment. • Snow set-up time of 24 h is recommended. • All but one model of projectile penetration in snow matched our results within 32%. Small (5.56 mm, 7.62 mm and 9 mm) and medium (12.7 mm) arms rounds were fired at snow-filled 1.5m cubic gabions in a mid-winter condition in Fairbanks, Alaska. The rounds were excavated and penetration by each ammunition type was measured. A distribution and average of penetration depth was determined. All 320 rounds fired were captured within 1.5m after entering the snow barrier. Comparison with published models of ballistics penetration of snow showed mixed results with several matching our data within 10% and all but one within 32%. However, most of these models are simplistic in that they accommodate limited variables and therefore may not be expected to perform well in all settings. We conclude that snow-based ballistics protection structures can be quickly and efficiently erected in suitable environments and with minimal size, can provide reliable protection against small and medium arms fire. [ABSTRACT FROM AUTHOR]

Abstract: In the paper theoretical and numerical model of two-phase flow of solid granular propellant and its products of combustion in the gun barrel during interior ballistic cycle is given. Two cases are considered: base ignition of propellant charge and ignition by igniter. The theoretical model includes the balance equations of mass, momentum and energy for both phases, as well as necessary constitutive laws. The igniter efflux in the propellant chamber is obtained by incorporation in the model the two-phase flow model of igniter function. The convergent, unconditionally stable, numerical procedure is formed to solve the system of equations of the theoretical model. An original procedure of numerical grid adaptation to the flow field increase, caused by the projectile motion down the gun bore, is developed. The TWOPIB code for the computation of whole interior ballistic cycle of ammunition is developed. Four kinds of experimental investigations were carried out:igniter function in open air, flamespreading through propellant charge in the fibreglass tube during base ignition or during ignition by igniter, and firing of 100mm APFSDS projectile. Verification of the theoretical–numerical approach by the comparison with experimental data is carried out. The great number of computational results is presented for the parameters that can not be measured, but which are necessary for more complete understanding of examined processes. The presented theoretical–numerical access enables, not only the complete optimisation of propellant charges, but more successful solutions of many interior ballistic problems. [Copyright &y& Elsevier]

In this study, the penetration behaviour of a Mild Steel Cored (MSC) round, 7.62 mm in diameter and 39 mm in length, commonly known as the AK47 round, was studied since it still forms an important part of the threat spectrum for personnel body armour systems. Likewise, boron carbide strike face materials were selected since this armour material is often the material of choice for ultralightweight body armour systems for protection against this particular threat. The presence of two, relatively soft, intermediate materials (the copper jacket and filler material of the bullet, and a fibre-reinforced polymer cladding layer on the ceramic) between the mild steel core and the boron carbide target was examined using reverse ballistics techniques, flash x-radiography and round recovery measurements. This was supported by selective numerical simulations using the computer code ANSYS-AUTODYN. It was found that stripping of the jacket, from the AK47 MSC rounds, makes a difference to its penetrating ability: the mild steel core is significantly reduced in length, and mass, when the jacket is not present. The magnitude of this effect is much greater than previously reported for high-strength steel-cored rounds and for tungsten carbide-cored rounds. The penetration event appears to be a twostage process: mushrooming of the mild steel core on, or near, the surface of the ceramic, followed by a linear erosion process as the core penetrates the ceramic itself. The second step has not been reported previously for MSC rounds. [ABSTRACT FROM AUTHOR]

Conventional ammunition easily deviates from the intended target. Its hit probability is reduced by such disturbance factors as fabrication errors, initial muzzle disturbance, initial velocity probable error, and stochastic wind effect. The effect of the above interference factors can be reduced by improving the shooting dispersion, ammunition, and gun or rocket engine structure. However, such improvements may fail to meet the operational requirements for modern warfare. Ballistic correction technique is a proposed trajectory control technique for precision strike with effective damage. Taking a 57 mm calibre projectile as research object, trajectory correction projectile with different aerodynamic layouts were designed. The aerodynamic characteristic, static stability, exterior ballistic characteristic and firing density of each projectile has been studied through research method of theoretical analysis and numerical calculation. These findings are considered instrumental in the trajectory correction technology research and engineering application. [ABSTRACT FROM AUTHOR]

Copyright of Internal Security is the property of Police Academy in Szczytno and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Overmatching occurs when body armour that has been designed to resist perforation by a specified projectile is perforated by a greater threat. This may result in wounding to the body armour wearer. In this work, overmatching of two types of police body armour was studied using two types of ammunition. The use of a 250-mm-long gelatine block to represent the depth of the human torso combined with armour panels mounted on the anterior and posterior of the block allowed for a more realistic simulation to be completed. There was some evidence to suggest that overmatching events could lead to increased levels of damage during a survivable incident compared with no body armour being present. This information is of interest to armour designers and medical personnel that might treat such wounds. [ABSTRACT FROM AUTHOR]

Identifying failure mechanisms in skeletal tissue allows a deeper understanding of the effects of specific projectile impacts on bone. While ballistic trauma in flat bones is largely researched, knowledge of how long bones react to gunshot impacts is limited in the literature. The impacts of deforming ammunition appear to produce higher levels of fragmentation; however, these have not been studied in depth. This study compares the damage to femora bone by HP 0.357 and 9 mm projectiles constructed with both full and semi‐metal jackets. Impact experiments were undertaken on a single‐stage light gas gun involving the use of a high‐speed video camera and full reconstruction of the bones to ascertain fracture patterns occurring in the femora. Higher degrees of fragmentation are likened to the presence of semi‐jacketed HP projectiles than jacketed HP projectiles. The observations of external facing beveled edges are believed to be associated with the increased separation of the jacket and lead core of projectiles. Additionally, experimentation has shown that the amount of kinetic energy lost postimpact is likely related to the presence or the absence of a metal jacket on an HP projectile. The observed data, therefore, suggest that the composition, rather than the configuration, of a projectile affects the type and extent of the damage. [ABSTRACT FROM AUTHOR]

Controlled, guided munitions can reduce dispersion in the shot, while providing the capability of engaging both stationary and maneuvering targets. The Netherlands Organisation for Applied Scientific Research has developed a fin-less control technology called Stagnation Pressure Reaction Control (SPRC) that takes stagnation pressure air and directs it sideways to control non-spinning projectiles. In a previous study, this technology was demonstrated at Mach 2 wind-tunnel conditions to achieve up to 1.5° controllable angle of incidence for a non-spinning, aerodynamically unstable projectile-like test object. In an operational scenario, the decelerating projectile will experience a decline in control force while the simultaneous forward shift of the center of pressure increases the need for control force. Furthermore, angles of incidence exceeding 1.5° will be experienced under realistic flight conditions, especially against maneuvering targets. This work addresses these challenges and presents an operational feasibility study for a practical application of SPRC in a non-spinning mid-caliber gun-launched projectile, using experiment data on control latency and force of the earlier study. It illustrates the combined effect of the control- and stability dynamics and underlines the potential of an SPRC projectile as a precisionoperation ammunition. This research revealed that SPRC technology can stabilize and control the hypothesized projectile in a direct fire scenario against stationary and maneuvering targets. [ABSTRACT FROM AUTHOR]

In the use of precision long guns, there is a continuous effort to improve accuracy and precision, in other words the accuracy of the weapons. These characteristics of the weapons are determined by the consistency of the whole "weapon system". In this article, we will explore the application of a method that offers a relatively low-cost development opportunity for sport shooters and shooters who use manual ammunition assembly (reloading), which can greatly improve the accuracy of the weapon. The method described in this article adjusts the time the projectile spends in the barrel to achieve a pre-calculated state of barrel deflection and vibration. To do this, it varies the ammunition assembly parameters (load size, seating depth, neck extraction force, etc.) to tune the internal ballistic processes in the weapon. The procedure is referred to in the literature as "Optimal Barrel Time" (OBT). [ABSTRACT FROM AUTHOR]

IMX‐101 and IMX‐104 are novel insensitive melt‐pour explosives developed and produced by BAE Systems at the Holston Army Ammunition Plant (HSAAP). The U.S. Army has selected these two explosives as common low‐cost replacements for legacy explosives TNT and Composition‐B used in indirect fire weapons such as artillery and mortar munition systems. This paper will review the literature related to the properties and manufacturing processes of IMX‐101 and IMX‐104, including their physicochemical, thermal, explosive, and sensitivity properties as well as their behavior in Insensitive Munition (IM) tests specifically designed to simulate real threats and hazards faced by a munition on the battlefield. IMX‐101 has been qualified and is currently fielded in the 155 mm M795 and the 105 mm M1 rounds. IMX‐104 has been integrated into various mortar projectiles including the 60 and 81 mm rounds and is being evaluated as a main explosive charge in the next‐generation 155 mm family of ammunition, which includes the XM1128 Extended Range High Explosive round and the XM1113 Rocket Assisted Projectile (RAP). [ABSTRACT FROM AUTHOR]

This paper presents a comparison of different .22, 9 mm Parabellum (9 mmP), .40 and .45 calibre ammunition. The different projectiles are analysed by performance, considering penetration depth into ballistic gel, while compared with the penetration depth after some clothing, such as a material used for jackets, are penetrated first. The velocity, kinetic energy, and kinetic energy per cross-sectional area of the projectile are analysed, to identify which calibre and projectile has the most impact force on a threat. A cost comparison of the different ammunition is shown, while an analysis is done of the cost per kinetic energy per cross sectional area, for different ammunition. [ABSTRACT FROM AUTHOR]

The article deals with the quantification of frangibility of the frangible bullets, which has high practical significance in evaluating the capability of a bullet to fragment upon impact on the target or obstacle and which allows comparison between the different types of the frangible bullets. In this article new original evaluation method of frangibility of frangible pistol bullets when hitting to the defined target is presented. [ABSTRACT FROM AUTHOR]

Among the different material surrogates used to study the effect of small calibre projectiles on the human body, ballistic gelatine is one of the most commonly used because of its specific material properties. For many applications, numerical simulations of this material could give an important added value to understand the different phenomena observed during ballistic testing. However, the material response of gelatine is highly non-linear and complex. Recent developments in this field are available in the literature. Experimental and numerical data on the impact of rigid steel spheres in gelatine available in the literature were considered as a basis for the selection of the best model for further work. For this a comparison of two models for Fackler gelatine has been made. The selected model is afterwards exploited for a real threat consisting of two types of ammunitions: 9 mm and .44 Magnum calibre projectiles. A high-speed camera and a pressure sensor were used in order to measure the velocity decay of the projectiles and the pressure at a given location in the gelatine during penetration of the projectile. The observed instability of the 9 mm bullets was also studied. Four numerical models were developed and solved with LS-DYNA and compared with the experimental data. Good agreement was obtained between the models and the experiments validating the selected gelatine model for future use. [ABSTRACT FROM AUTHOR]

The PELE ammunition is characterized by a low-density filling material surrounded by a high-density brittle jacket material. An analytical model describing the fragmentation of this ammunition behind a target plate is presented. This model assumes uniaxial strain in the filling and uses the Ranking–Hugoniot relations to calculate the material state. In addition, shock and rarefaction wave interactions at the target free surface and the filling/target interface are accounted for, as well as the radial rarefaction originating from the jacket outer surface. This allows the calculation of the pressure evolution in the filling and the radial acceleration of the jacket at any axial position along the projectile. This model aims at improving previously published analytical models where the acoustic wave approximation was used and the wave interactions were neglected. Experimental results (Paulus and Schirm, 2006) are used to validate the analytical model for different target materials (aluminum and steel), target thicknesses (3 mm and 8 mm), filling materials (polyethylene and aluminum) and impact velocities (900 m/s to 3000 m/s). A qualitative comparison based on X-ray photographs reveals similar features between the model and the experiments, such as smaller and lighter fragments with a greater radial velocity at the front of the projectile compared to the fragment characteristics at the back of the projectile. A quantitative comparison based on the maximum radial velocity of the fragments shows on average a 20% difference between the analytical and experimental results for all impact conditions considered. Despite this difference, the analytical trend follows more closely the experimental one compared to the acoustic approximation especially at high impact velocities. In addition, the acoustic approximation fails to reproduce the jacket fragmentation pattern since the fragmentation length of the jacket is significantly under-predicted. A numerical simulation is also presented using the ANSYS Autodyn 14.0 software. The results show that the numerical and analytical pressure evolution in the filling and the radial velocity of the jacket are in very good agreement, verifying the uniaxial strain assumption. This agreement (together with the experimental agreement) thus suggests that the Rankine–Hugoniot relations, the wave interactions and the radial rarefaction wave must all be included in the model to adequately describe the fragmentation of the PELE ammunition behind a thin target plate. [ABSTRACT FROM AUTHOR]

A novel inertial measurement unit scheme with five accelerometers and two gyros (5A2G) is proposed in this paper to achieve high precision measurement in high dynamic environment. The three channels are decoupled during the angular velocity calculation procedure to ensure the precision and efficiency. The yawing and pitching angular velocities are directly measured by gyros, while only the rolling angular velocity is inferred indirectly from the rolling angular information vector composed of rolling angular acceleration and quadratic component of rolling angular velocity. Based on the proposed scheme, the configuration ascertainment problem for acquiring the required installation parameters of accelerometers is transformed into a constraint optimization problem with the objective of minimizing the error of rolling angular information vector. A single channel rolling angular velocity calculation model is then established on the basis of the optimal configuration and the extended Kalman filter algorithm is utilized for state estimation. Simulations are implemented and results indicate that the optimal 5A2G scheme is feasible for high-speed rotating ammunition. [ABSTRACT FROM PUBLISHER]

To study the influence of the structural parameters of the ammunition liner of small-caliber ammunition on the forming characteristics of the projectile, an integrated circumferential multiple explosively formed projectile (MEFP) warhead with an integrated shell and the liner was initially designed, and the wall thickness of the liner is variable. LS-DYNA finite-element software is used to simulate the integral circumferential MEFP of the preliminary design, based on the numerical simulation results, the influence of the thickness at the center of the liner, and the curvature radius of the liner on the shape and velocity of the formed projectile. The numerical simulation results show that when the thickness of the center of the liner is constant and the curvature radius increases gradually, the velocity of the formed projectile decreases and the length: Diameter ratio of formed projectile decreases gradually. When the curvature radius of the liner remains unchanged, the velocity of the formed projectile decreases with the increase of the thickness of the center of the liner, and the shape of the formed projectile does not change significantly. The results show that when the design of integrating the shell and the liner was adopted for the integral circumferential MEFP warhead, the shape of the formed projectile is greatly affected by the curvature radius of the liner (curvature radius of inner and outer walls of the liner), but less by the thickness of the center of the liner. The velocity of the formed projectile is affected by the curvature radius of the inner and outer walls of the liner and the thickness of the center of the liner. Moreover, the influence of the thickness of the center of the liner on the velocity of the formed projectile is greater than that of the curvature radius of the outer wall of the liner. [ABSTRACT FROM AUTHOR]