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Shooting incidents are often portrayed as resulting in a sometimes violent backwards displacement of the victim. This opinion is also not infrequently held by expert witnesses. The physical force responsible for this would be momentum (mass x velocity). The physics of momentum in ballistic injury is explained in detail. The maximum momentum transferred from different small arms projectiles including large calibre rifles and a 12-gauge shotgun only results in a backwards motion of a 80 kg target body of 0.01-0.18 m/s, which is negligible compared to the velocity of a pedestrian (1-2 m/s). Furthermore, counterbalance is constantly maintained by neurophysiological reflexes. So the effect of the momentum transferred from the missile is virtually zero and there is no backwards motion of the person shot. Empirical evidence verifying these calculations can be obtained from hunting big game, from human gunshot victims and from a video documentary demonstrating the lack of any backwards motion of a person wearing body armour after hits from a centre fire rifle. So the alleged backwards hurling of a person shot is nothing but a myth which should be refuted not only because it is incorrect but also because it can result in miscarriages of justice.

U.S. military forces increasingly find themselves in situations compatible with the use of non-lethal weapons. Extending the range and spheres of influence of these non-lethal weapons is considered essential as an option in future conflict scenarios. With this in mind, the U.S. Army Research Laboratory (ARL) at Aberdeen Proving Ground, Maryland, and the U.S. Army Armament Research Development and Engineering Center (ARDEC) at Picatinny Arsenal, New Jersey, have joined together in an effort to produce a non-lethal artillery projectile. With support from the Los Alamos National Laboratory, New Mexico, and Edgewood Chemical Biological Command, Maryland. ARDEC has accepted the challenge of selecting and tailoring the payload and expulsion issues. while ARL will focus on its traditional area of expertise in ballistics and will develop technologies for a non-lethal carrier for the selected payload. The goal of this effort is to project non-lethal payloads to ranges similar to those of standard artillery.

To recognize the targets state in a battlefield after shots, it's possible to send a video sensor with the same ballistics than real ammunitions. This article describes the modeling of observation ammunition using simulation workshop CHORALE and AMOCO. Before real trials on a battlefield and to define the final features of an embedded video sensor, it is necessary to modeling each part of the behavior of the ammunition. The goal of this simulation is to know how the ammunition with its movements as the rotation, pitch, yaw can see the proving ground and what values of parameters it is possible to set into the embedded sensor. To perform the simulation, we need of a ballistics model taking into account the geometric form of the projectile. This ammunition flights over a battlefield so we need a realistic 3D scene model taking into account the atmospheric conditions, real target, geometric target and all existing things on a real proving ground as building, forest and so on. The frame seen by the sensor is modified by its transfer function. The video sensor model takes into account lot of functional parameters as Optic, Detector and electronic function. An algorithm takes place at the incoming step in the sensor model and takes into account the rotation during the integration time. Each model calculates independently.

A model to predict the ballistic ricochet of rod penetrators is presented. The model is based on the premise that the phenomenology of ricochet is one where the impacting rod feeds into a plastic hinge located at the rod/target interface, and is thus diverted from a penetrating trajectory. The model is offered in both a full and simple form. The full form of the model arises from the simultaneous solution of a series of six algebraic equations that constitute the momentum-flux/force and moment balances upon the plastic hinge, subject to various material and kinematic constraints. This full model is not solvable in closed form, but rather by way of algorithm. The simple form of the model, by contrast, dispenses with the moment balance and makes several simplifying kinematic assumptions that permit the ricochet criterion to be expressed as a closed form inequality. Such a simplified form is along the lines of, and thus directly comparable to, several prior ricochet models in the literature. Compared against 24 ballistic tests, comprising two separate ricochet studies, the current model (in both forms) shows an improved ability to predict the ballistic ricochet of impacting rod projectiles. The simple form of the current ricochet model actually proved the best predictor of the ballistic data.

Hypervelocity impact experiments that reproduce on-orbit collisions between micrometeoroids or orbital debris and space structures are commonly performed by means of propellant-driven two-stage light-gas guns. Such devices accelerate projectiles using the thrust of a light propellant gas that is compressed to high pressure and temperature by a piston running in a pump tube. Though these guns have the unique capability of accelerating particles up to 9 km/s, many components of the gun must be checked and/or substituted after each shot making test sessions long and expensive. In order to have a lot of and many different types of hypervelocity impact data, the Center of Studies and activities for Space CISAS “G. Colombo” of Padua University developed a high-shot-frequency two-stage light-gas gun that can increase the shot repetition rate of standard facilities by a factor of 5 or more and at the same time reduce the shot cost by a factor of 2 or more. This is made possible through the use of special mechanical and diagnostic solutions that were designed to operate the gun for more than 50 shots in sequence without having to carry out maintenance operations. This article presents the design and operation of the CISAS two-stage light-gas gun damping system, which is one of the subsystems that makes it possible to achieve high-shot frequency. The damping system is in charge of controlling the piston oscillations in the pump tube, making it possible for the piston to withstand more than 100 shots without any damage. In particular, the damping system avoids piston strikes onto the gun head at the end of each compression stroke and allows the piston to be positioned at the base of the pump tube after each shot. The sensitivity of the piston oscillations to the damping operations and main subsystem design parameters were identified using numerical simulations, carried out according to a model that describes every working phase of the gun. Moreover, in this paper, the technical solutions for the damping system implementation are presented and the numerical predictions are compared with experimental results. For the CISAS high-shot-frequency gas gun, an efficient damping system proved to be a fundamental requirement to reliably accelerate 100 mg projectiles above 5 km/s and 70 mg projectiles at 5.5 km/s with a shot frequency of 10 shots per day at least, including the time needed for replacing the target and pumping down the target vacuum chamber.

Characteristic markings on the cartridge and projectile of a bullet are produced when a gun is fired. Over thirty different features within these marks can be distinguished, which in combination produce a ”fingerprint” for identification of a firearm. Given a means of automatically analyzing features within such a firearm fingerprint, it will be possible to identify not only the type and model of a firearm, but also each individual weapon as effectively as human fingerprint identification can be achieved. In this paper, a new analytic system based on fast Fourier transform (FFT) for identifying the projectile specimens digitized using the line-scan imaging technique automatically is proposed. Experimental results show that the proposed system has the ability of efficient and precise analysis and identification for projectiles specimens.

This report compares a priori gun-projectile dynamic simulations to experimental ballistic jump test data for seven 120-mm prototype kinetic energy (KE) projectiles and describes the methodology used for the comparison. The projectiles contain significant differences in their charge, subprojectile, and sabot designs that span the design parameters encountered in KE cartridge development. In such tests, four or more sets of orthogonal radiograph images (x-rays), which are typically used to characterize the state of the projectile at muzzle exit, can be directly compared to predictions from ARL's gun-projectile dynamic simulation (GPDS) codes. The results from these comparisons show that the GPDS codes were able to predict the ballistic experimental results except for the transverse center-of-gravity jump velocity in two cases. For the two cases, the difference in predicted and experiment is shown to occur when a high average rate is seen at the muzzle exit and is probably due to the timing error associated with muzzle exit.

The characteristic markings on the cartridge and projectile of a bullet fired from a gun can be recognised as a "fingerprint" for identification of the firearm. Over thirty different features within these markings can be distinguished, which in combination produce a "fingerprint" for identification of a firearm. The analysis of marks on cartridge casings and projectiles that have been fired, provides a precise tool for identifying the class of firearm from which a bullet was discharged. The measurement of features on ballistics cartridge cases and projectiles allow precise ballistics metrics to be obtained of cartridge case and projectile class characteristics for the identification of the make and model of the firearm. These different features within these markings and patterns can be identified, which in combination produce a "fingerprint" for any type of firearm. A variety of features can be observed under moderate or high magnification of the specimen. However, not all features are observable for all weapons under all conditions of discharge. This situation represents the classical situation of "missing data" when attempting to demonstrate "similarity" between specimens. This condition is overcome by seeking "feature by feature" comparisons without achieving identical matching for the crime scene and test specimens. This paper will describe progress in the development of a multi-dimensional cluster analysis model for forensic ballistics specimens to identify the type of weapon that produced these ballistics specimens. The cluster analysis will provide classification that is based on scalar shape and measurement parameters for the three-dimensional features of class characteristics. These class characteristics include calibre, firing pin mark, ejector mark, and extractor mark for the cartridge case; and number and widths of land and groove marks, and the direction of twist of rifling on the projectiles. The selection of appropriate class characteristics for cartridge and projectile can be mapped in N-dimensional space to provide clustering for particular weapon types. By mapping the crime scene specimen to the multidimensional ballistics data, the possibility of a match for identification may be achieved. This project has the potential to significantly improve the effectiveness and efficiency of tracing of firearms used in criminal activities.

In recent years, a para-phenylene benzobisoxazolc fiber, Zylon (registered trademark of the Toyobo Company), has surfaced as a potential candidate for body armor to possibly replace Kevlar (registered trademark of DuPont). Zylon's effectiveness depends on its ballistic properties as well as its mass in comparison with Kevlar. The present extended investigation focuses on determining the ballistic limit and the V50 velocity for 10, 20, and 30 stitched plies of Zylon using standard North Atlantic Treaty Organization 9-mm nonrotating strikers. This report concentrates specifically on the ballistic limit of 10-ply Zylon, as well as the effect that impact location has on perforation. It was also discovered that many other factors affect the ballistic performance, including slip of the fabric in the holder, the preparation of the shell, and the amount of fiber damage present. These aspects will be considered when evaluating Zylon's performance and determining whether or not it is indeed superior to Kevlar for applications in body armor and personnel protection. The first instance of perforation for 10-ply Zylon occurred at an initial velocity of 341.4 m/s, and the highest initial velocity for a ricochet was 566.2 m/s.

The identification of firearms from forensic ballistics specimens is an exacting and intensive activity performed by specialists with extensive experience. The introduction of imaging technology to assist the identification process of firearms has enhanced the ability of forensic ballisticians to conduct analyses of these specimens for identification. The characteristic markings on the cartridge and projectile of a bullet fired from a gun can be recognised as a fingerprint for identification of the firearm. Forensic ballistics imaging has the capacity to produce high-resolution digital images of cartridge cases and projectiles for matching of crime scene specimens to test specimens. Projectile bullets fired through the barrel of a gun will exhibit extremely fine striation markings, some of which are derived from minute irregularities in the barrel produced during the manufacturing process. The examination of these striations on the land marks and groove marks of the projectile is difficult using conventional optical microscopy. However, digital imaging techniques have the potential to detect the presence of striations on ballistics specimens for identification matching. This paper describes a linescan imaging technique to examine the striation markings on the land marks and groove marks of projectiles for positive identification. The paper discusses the application of the technique to cylindrical forensic ballistics specimens, and the potential of the technique for image matching. Digital images of land marks and groove marks of projectiles produced by the line scan technique are presented, and analyses of the images are conducted.

The overall objective of this MURI program was to develop a new class of lightweight armor materials in the form of layered ceramics and metal ceramic composites. This entailed developing novel processing techniques, extensive dynamic experimental evaluations and modeling as well as new analysis and experimental methods. The research program consisted of four major areas: manufacture of layered ceramics and ceramic metal composites for armor, constitutive modeling and damage mechanisms, ballistic penetration experiment and simulation, and development of advanced experimental and computational methods. Briefly, in the processing area, two versatile routes for production of layered and graded multilayer ceramics have been developed: sequential centrifugal casting and lamination of tape-cast ceramics. In the mechanics and modeling area, microstructural effects on the response and failure in heterogeneous materials under dynamic loads were studied and modeled. New experimental methods were developed with the aid of inverse methods in conjunction with the FEA. Improved computer codes for simulation of projectile penetration were achieved.

A system for enemy jet aircraft detection, targeting, and elimination using ballistic projectiles is demonstrated using a scaled down model. The enemy jet aircraft is a plastic 1/48 scale model of a F-16C tactical air defense fighter. An optical target acquisition system is used to locate the jet aircraft in 3-dimensional space. Once the aircraft is located, a microcontroller then calculates the required ballistics to fire a 'ping pong ball' projectile at the target. A pneumatic reservoir is used as a pressure source. The main gun uses a high velocity jet stream to propel the projectile down the firing tube. Upon operator command, the microcontroller will fire the projectile eliminating the Bogie. Communication occurs through a 10 button key pad and a 40 character 2-line display on the main control unit. This project demonstrates the maximum I/O usage of the MC68HC11 EVB Evaluation Board at the minimum cost. It incorporates mixed signal integration of analog and digital signals using proven noise reduction techniques. This project explores basic engineering equations and included fabrication of a pressure sensor using the storage container as the sensing element.

The potential exists for the detection of ballistics projectiles in flight by electro-optics and allied optical systems which provide discrete numerically coded output signals for the determination of the position and diameter of a projectile passing through the test region. This paper evaluates these technologies that could be applied to the development of a forensic ballistics projectile location system. The requirements of forensic ballistics research for projectile location are discussed and the properties of the electro-optical technologies that favour application to the development of the high-resolution projectile location systems are examined. This paper considers a selection of optical projectile location systems in order to exhibit the principles of operation of detecting both subsonic and supersonic bullets in flight. The forensic applications of the precise measurements of the parameters associated with the motion of the projectile will permit a better understanding of the behaviour of weapons and projectiles in the solving of weapons-related crime.

The characteristic markings on the cartridge and projectile of a bullet fired from a gun can be recognised as a "fingerprint" for identification of the firearm. Over thirty different features can be distinguished. The intelligent imaging of the class characteristics of ballistics specimens will provide the potential to identify the make and model of the firearm. Precise measurement of features allow ballistics metrics to be obtained for the identification of the weapon. This paper will describe progress in the development of a multidimensional cluster analysis model for forensic ballistics specimens. The cluster analysis will provide classification that is based on scalar shape and measurement parameters for the 3D features of class characteristics. The selection of appropriate class characteristics for cartridge and projectile can be mapped in N-dimensional space to provide clustering for particular weapon types. By mapping the crime scene specimen to the multidimensional ballistics data, the possibility of a match for identification can be achieved.

The Army Research Laboratory has developed a scaleable, 3D, multiphase, computational fluid dynamics (CFD) code with application to gun propulsion (interior ballistics) modeling. The NGEN3 code, which incorporates general continuum equations along with auxiliary relations into a modular code structure, is readily transportable between computer architectures and is applicable to a wide variety of gun propulsion systems. Two such systems are the Army's Modular Artillery Charge System (MACS) and the Future Combat System (FCS). The MACS is being developed for indirect fire cannon on both current and developing (e.g., Crusader) systems. The efficiency of the MACS charge is dependent on proper flamespreading through the propellant modules; a process that has been repeatedly demonstrated in gun firings, successfully photographed using the ARL ballistics simulator, and numerically modeled using the NGEN3 code. The FCS requires weapons systems exhibiting increased range and accuracy. One of the technologies under investigation to achieve these goals is the electrothermal-chemical (ETC) propulsion concept, in which electrically generated plasma is injected into the gun chamber igniting the high-loadingdensity (HLD) solid propellant charge. NGEN3 code development and application to the MACS and FCS is currently a DoD HPC Challenge Project (No. 112) and is being greatly advanced by access to the DoD high performance computers (HPCs). Associate Fellow AIAA. Propulsion Physics Team Leader, Ballistics and Weapons Concepts Division, Weapons and Materials Research Directorate. Mechanical Engineer, Propulsion Physics Team, Ballistics and Weapons Concepts Division, Weapons and Materials Research Directorate. This paper is declared a work of the U.S. Government and is not subject to copyright protection in the United States. INTRODUCTION A solid propellant gun system consists of a reaction chamber connected to a gun tube through which a projectile is guided once propelled by pressurization of the chamber. Chamber pressurization is accomplished by placing a solid propellant (SP) charge in the chamber and igniting it by various means. Current SP charges are generally complex structures consisting of hundreds or even thousands of distinct regularly formed (e.g., spherical, cylindrical) grains, which may be loaded in either regular or random arrangements. In addition to small-scale voidage between grains (i.e., porosity) many charges also contain large-scale voidage (i.e., ullage), which surrounds the entire charge (such as when the charge does not fill the entire chamber volume) or separates distinct subcharges (i.e., increments or modules) that together comprise the whole charge. The addition of energy to the chamber, usually near the gun breech, or rearmost end of the chamber, and in some cases through a tube extending along the centerline of the chamber, ignites the SP. In general, all of the grains are not ignited simultaneously, but an ignition flame spreads from the breech to the projectile base. The burning of the SP transforms chemical energy into heat as hot gases evolve from the surface of each grain of propellant. Initially the projectile resists movement allowing the pressure in the chamber to climb rapidly. Since the burn rate of the propellant is proportional to the pressure, hot gases are produced at an accelerated rate until peak pressure is reached in the chamber. Movement of the projectile down the gun tube, usually slight before peak pressure and much more significant afterwards, causes the chamber volume to increase, and generates rarefaction waves, which lower the pressure and thus the burn rate of the propellant. Upon ignition and burning, the gas dynamic flowfield in the gun chamber takes on a highly complex structure that includes the dynamics of propellant motion and combustion and various gas dynamic flow phenomena such as turbulent mixing, highly transient pressure waves, steep gradients in porosity and temperature, nonideal thermodynamics, and gas generation.

With the development of plasticity theory in the 1940s and 1950s, the modeling of penetration has become increasingly analytical and accurate. Currently, analytic penetration models are able to accurately predict depths of penetration for simple penetration geometries where the target and projectile are metals. The most accurate models use sophisticated plasticity analysis to obtain target resistances, but they usually end up expressible as relatively simple explicit differential equations. The most promising development in recent years is the centerline momentum balance, and this technique will be reviewed with some discussion of the meaning of terms by way of first principle physics. A recent model that successfully predicts ballistic limits of fabrics will also be discussed. In addition to addressing what is known, the most pressing questions that need to be answered and what is currently known on those problems will be discussed. Questions include: the transition from eroding to rigid penetration; the...

Avehicle proceeding up an inclined ramp will become airborne if the ramp comes to a sudden end and if the vehicle fails to stop before it reaches the end of the ramp. A vehicle may also become airborne if it passes over the top of a hill at sufficient speed. In both cases, the vehicle becomes airborne if the point of support underneath the vehicle falls below the trajectory that would be followed by the vehicle in the presence of gravity alone. When the vehicle becomes airborne, the normal reaction force exerted by the ramp or the hill drops to zero, first on the front wheels and then on the rear wheels. Just prior to the vehicle's becoming airborne, the normal reaction force on the rear wheels acts to exert a torque on the vehicle, causing the vehicle to rotate. After the rear wheels become airborne, the vehicle will continue to rotate until it lands some distance from the launch point.

In recent years, physicists, engineers and medical scientists have tried to demonstrate the biomechanics of gunshot wounds with numerical methods and experimental observations. Currently, the finite element method (FEM) is the most widely used numerical method among the studies related to ballistic wound injuries. However, when the FEM is used for the penetration analysis, the path of the projectile in the skull is subjected to extremely large deformations which will introduce errors due to distortion of elements. To overcome this error, the meshfree technique was established to simulate the gunshot wound as a preliminary study in which the skull was modeled by smoothed particle hydrodynamics (SPH) and the projectile was modeled by nondeformable rigid elements. In order to simulate a realistic penetration phenomenon, orthotropic material properties were defined for different regions (forehead, zygomatic and mandible) with material principal axis along the surface of the bones. Human response to the ballistics impacts were determined in terms of force occurring along the pathway of the bullet in the skull, residual velocity of the projectile and penetration depth. The obtained results were compared with the data reported in literature. As a result, mechanical behavior of the head under ballistic impacts simulated by the SPH, compared well with the results determined by the data given in literature, which indicates the applicability of the SPH method as a powerful technique in simulating different gunshot wound mechanisms.

The article of record as published may be found at http://dx.doi.org/10.1520/JTE20130107 This paper describes a cost effective automated methodology to analyze launch video of artillery projectiles. Image processing and computer vision techniques are used to segment and classify the projectile shape in each video frame. Within minutes of being fired, the initial position, velocity, and orientation history of the projectile in three-dimensional space is determined at the gun site. An overview of several standard methods used by the Army to characterize pitching and yawing motion of projectiles is included, as well as a discussion of the limitations of these methods. Results from real artillery testing using the automated video analysis method are validated through comparisons to results measured using conventional techniques.

With the new requirements of the future combat systems (FCS), gun-launched projectiles will most likely be decreasing in diameter and increasing in muzzle velocity. In addition, these projectiles will be carrying entire electronic systems, specifically, global positioning system (GPS)/inertial guidance and terminal homing. These systems will sense during the flight and terminal environments of the projectile and will provide data links (probably two-way telemetry) for system diagnostics and dynamic re-targeting. Most of these sensing elements involve various antennae operating at a variety of frequencies ranging from GPS (1.5 GHz) to millimeter wave seekers (94 GHz) to optical seekers (1 PHz). Because of packaging constraints, these systems are likely to be placed forward on the projectile body. All these antennae require a protective "window" for transmitting and/or receiving signals. Based on the location of these systems, that window is usually described as the projectile radome. The radome must withstand the cannon launch and ballistic environment. The intense aero-heating of supersonic flight softens polymers, thus reducing the structural integrity. Of course, it is obvious that the radome must perform well electronically across a possible wide band of radio frequencies. This report studies the use of several (polymer types) materials, which can be machined to create a radome of a desired shape. These polymers, which are either extruded or molded into stock shapes, were chosen based on the dielectric constant (relative to air, between 3 and 4) and thermal and structural properties. A generic radome geometry was selected to perform the thermal and structural analyses. An older yawsonde geometry, which was flight tested, was also analyzed.

Modem armored vehicles are equipped with a variety of sensitive components on board, such as computers, telecommunication equipment, range finders, and infrared devices. One potential failure to these sensitive electronic components is due to the high frequency shock wave transmitted through the structure due to impact loads. Failure or malfunction of the electronic equipment can severely damage the combat capability of the armored vehicle, even though the crew survives and the vehicle retains its structural integrity after the impact. These impact loads can be from air blast, land mine detonation, or a projectile penetration. A good understanding of the loading functions due to blast, impact, and penetration, and the stress waves transmitted through the complex vehicle structure due to these impulsive loads, facilitates the improved combat capability of the armored vehicle. Advantages of each of the approaches will be presented, including a comparison of numerical simulations with experimental data.

This chapter describes the small arms exterior ballistics model. Exterior ballistics is the study of the motion of a projectile fired from a gun. Physical forces that act on the projectile have been under study for more than a century. Trajectories, the curved paths of projectiles, have been described by differential equations. Solution by integration has yielded further information about these physical forces. Researchers have concentrated their studies of exterior ballistics mainly in the area of military applications. To initiate systems analysis, ballistics data were sought from the test laboratories of two manufacturers, Remington and Winchester. Both, as a matter of policy, refused the request on the grounds of confidentiality and suggested that some data were already available in published form. However, despite the refusal to provide test data, systems modeling becomes an even more attractive approach in that knowledge items provide a suitable substitute for data in building a small arms exterior ballistics model.

Hunting firearm injuries and fatalities from ricocheted bullets play a minor, but still important, role in forensic medicine and shooting reconstruction. Especially in the area of critical ricochet angles a ballistic analysis is essential to be able to reconstruct hunting accidents. The aim of this study is to analyze ricocheted rifle projectiles (.30-06 Bionic Black and .30-06 Oryx) and shotgun slugs (cal. 12 Brenneke original) from frozen and non-frozen concrete, as well as their ballistic injury potential at a simulated shooting distance of 100 m (rifle projectiles) and 20 m (slugs). Each projectile had a v100 velocity between 370 m/s (shotgun ammunition) and 740 m/s (rifle ammunition) and was shot at an incident angle between 2–20° (rifle ammunition) and 5–35° (shotgun ammunition). To record the angle of ricochet and target energy of each ricocheted projectile, a polycarbonate wall with a reference scale, as well as ballistic soap were used as a final target. At a shooting distance of 100 m, non-ricochet shots are only possible from high seats, but not from deer stands. The critical shooting angle showed a rather high variation for both rifle and shotgun ammunition and was noted between 1.25 times (shotgun ammunition) and 2.5 times (rifle ammunition) higher for frozen concrete compared to non-frozen concrete. All tested ammunition showed remarkable high variations in the ricochet’s angular deviation. Upon the impact of a ricochet, energy levels of over 1000 J were realized with significant injury potential to underlying organs.

Background: Magnetic resonance imaging (MRI) is rarely used for preoperative assessment of shotgun injuries because of concerns of displacing the possibly ferromagnetic foreign body within the surrounding tissue. Methods: A total of 56 different projectiles underwent MRI testing for ferromagnetism and imaging quality in vitro and in pig carcasses with a commercially available 1.5-MRI scan. Image quality was compared with that of computed tomographic scans. Results: Projectiles with ferromagnetic properties can be distinguished easily from nonferromagnetic ones by pretesting the motion of an identical projectile within the MRI coil. When ferromagnetic projectiles were excluded, MRI yielded the more precise images compared with other imaging techniques. Projectile localization and associated soft tissue injuries were visualized without artifacts in all cases. Conclusions: When ferromagnetic foreign bodies are excluded by pretesting their properties within the MRI with a comparative projectile, MRI portends an excellent imaging procedure for assessing the extent of injury and planning the removal by surgery.

During the course of the project we conducted two sets of fundamental experiments in penetration mechanics in the LLNL Terminal Ballistics Laboratory of the Physics Directorate. The first set of full-scale experiments was conducted with a 14.5mm air propelled launcher. The object of the experiments was to determine the ballistic limit speed of 6Al-4V-alloy titanium, low fineness ratio projectiles centrally impacting 2024-T3 alloy aluminum flat plates and the failure modes of the projectiles and the targets. The second set of one-third scale experiments was conducted with a 14.5mm powder launcher. The object of these experiments was to determine the ballistic limit speed of 6Al-4V alloy titanium high fineness ratio projectiles centrally impacting 6Al-4V alloy titanium flat plates and the failure modes of the projectiles and the target. We employed radiography to observe a projectile just before and after interaction with a target plate. Early on, we employed a non-damaging ''soft-catch'' technique to capture projectiles after they perforated targets. Once we realized that a projectile was not damaged during interaction with a target, we used a 4-inch thick 6061-T6-alloy aluminum witness block with a 6.0-inch x 6.0-inch cross-section to measure projectile residual penetration. We have recorded and tabulated below projectile impactmore » speed, projectile residual (post-impact) speed, projectile failure mode, target failure mode, and pertinent comments for the experiments. The ballistic techniques employed for the experiments are similar to those employed in an earlier study.« less

The primary purpose of the Light Forces Program is to improve the effectiveness of fire from the infantry mortar. Advances in microelectronics, sensors, and power supplies make it possible to design and build a miniature, one-dimensional, range correction module (RCM) for the mortar. This report focuses on the flight testing of an RCM prototype device for the 81-mm mortar. The objective of testing the concept was to demonstrate the structural integrity and the drag authority of the design. Based on the experimental data, it can be seen that the undeployed range control modules do not affect the overall drag of the projectile. It can also be seen that when the RCM deploys, it has a significant effect on range. Experimental data obtained from the test indicate that the undeployed RCM does not change the ballistic characteristics of the shell; however, when deployed, the RCM does provide a significant method of controlling range.

A spent cartridge case exhibits characteristic markings (firearm fingerprint) that can be used to identify the type, and possibly make, of weapon in which the cartridge was fired. This paper details research into the use of discriminant analysis for the purpose of matching spent cartridge cases to specific make and model of firearms. A fired projectile can also be analyzed by measuring the class characteristics such as land mark, groove, mar, and twist ratio. A personal computer (PC) based prototype software application called FireBall will also be described in detail.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The objective of this work was to document the numerical simulation of the cannon projectile blow-by flow for a Zone six firing of an M549A1 with XM230 charge. The steady, axisymmetric flow was determined by use of the NPARC Computational Fluid Dynamics Code, given inflow boundary values at points on the ballistics path. We computed pressure distributions on the projectile, assuming a smooth cannon surface. Integration of the distribution over the projected lateral surface of the projectile gives an estimated side force of 500,000 pounds on the projectile as it enters the brake section of the tube. In a yawed attitude, such forces can effect inertial instabilities on the projectile which, in turn, contribute to balloting and mechanical wear of the tube. The same numerical solution computes local heat transfer rates on the obturator and rotating band surfaces. The effect of blow-by flow heat transfer on tube erosion is a factor that is not well understood. An extension of the present work will provide a basis for further understanding the combined effects of abrasive and chemical erosion. The present computations assume that the wear gap between projectile and cannon wall is 0.020 inch and that the obturator protrudes 70% into the gap. Results are presented at two points on the ballistics trajectory, 2.212 and 5.256 meters from the rifle origin. Local heat transfer to the barrel wall was obtained for projectiles with and without obturator and band. At the 2.212 meter location, the latter yielded maximum local heat transfer rates on the barrel surface that exceeded 30 times the heat transfer computed at 1.7 inches upstream of the projectile's base (i.e., in the projectile's wake boundary layer). With the obturator and band, and at the same travel point, the heat transfer ratio peaked at 2040, with the wake heat transfer computed at 6.7 inches upstream of the projectile's base.

Computational fluid dynamics (CFD) solutions of the full Navier-Stokes equations along with finite-rate chemical kinetics, are used to numerically simulate the reacting in-bore flowfield for a 120mm ram accelerator projectile propulsion system. Various unsteady flow phenomena are investigated, including projectile starting, obturator discard, and high-velocity unstarting. These simulations illustrate the importance of obturator discard dynamics in achieving a successful starting of the ram acceleration process. However, once started, high projectile velocities can induce an unstart if the combustion wave precedes the projectile under certain conditions. In addition, a CFD code validation case is presented for low pressure, steady flow, hydrogen/oxygen combustion around a wedge as compared to Schlieren/PLIF data from Stanford. Introduction Experimental testing and gasdynamic modeling of the ram acceleration technique for in-bore projectile propulsion has been investigated at the U.S. Army Research Laboratory (ARL) under the Hybrid Inbore RAM (HIRAM) propulsion program. This research program seeks to provide a highly efficient method of achieving hypervelocity (> 3 km/s) projectile gun-launch for use in high speed impact testing applications. The ARL ram accelerator system used a 120-mm (bore diameter) tube which was modeled after the 38-mm system at the University of Washington. Numerical solutions of the Navier-Stokes equations have been obtained at the ARL via computational fluid dynamics (CFD) codes for non-reacting and reacting, two-and three-dimensional flows. These codes are being used to investigate the complex gas dynamic physics of ram accelerator projectile propulsion. A variety of CFD techniques have been brought to bear on this problem, including models for chemically frozen (non-reacting) gas, finite-rate global and multiple step chemical kinetics, and equilibrium chemical processes. Accurate numerical simulation of hydrocarbon-based reacting flow creates a very great demand on computational resources since the number of intermediate species and the number of kinetic steps for typical hydrocarbon fuels are prohibitively large. Global reaction mechanisms based on up to thirty-two steps have therefore been investigated for use in preliminary design studies. Within several hours on supercomputers, viscous and chemically reacting gas dynamic simulations are used to assess the influence of projectile velocity, tube fill pressure and mixture composition, and projectile geometry on species consumption, tube wall pressure and projectile thrust. These studies are being used to seek optimum performance for the 120-mm ram accelerator with minimal gun firings. In particular, significant advances in CFD * Aerospace Engineer, Ballistics &; Weapons Concepts Division. Associate Fellow AIAA. This paper is declared a work of the U.S. Government and is not subject to copyright protection in the United States. • modeling for ram acceleration have been made at the ARE." Recently, ARL CFD models have been modified to simulate the unsteady coupling between the launch gun and the ram accelerator. In the Army experimental gun, projectile transition from the conventional (solid propellant) launcher to the accelerator was made through a transition/vent section. This section decouples the launch gun movement from the accelerator and vents combustion gases from the conventional launcher. Redesign of the ram accelerator for Navy applications has required that the ram accelerator operate without the vent section. The removal of the vent section requires that the CFD code be linked to an interior ballistics (IB) simulation of the launch gun in order to supply the pressure behind the obturator. The IB code must be able to adjust to the pressure on the forward face of the obturator, supplied from the CFD code simulating ram combustion. Simulation of ventless ram acceleration has been accomplished. Reacting Flow Model The chemically reacting hypervelocity flow field around a body is numerically simulated using a computer code based on computational fluid dynamics. The ARL-NSRG2 code solves the 2D/axisymmetric, unsteady, real-gas Navier-Stokes equations including equations for chemical kinetics and diffusion. These partial differential equations are cast in conservation form and converted to algebraic equations using a finite-volume formulation. The conservation law form of the equations assures that the end states of regions of discontinuity (e.g., shocks, flames and deflagrations) are physically correct even when smeared over a few computational cells. Solution takes place on a mesh of nodes distributed in a zonal fashion around the projectile and throughout the flow field such that sharp geometric corners and other details are accurately represented. The Navier-Stokes equations for 2D/axisymmetric reacting and unsteady flow are written in the following conservation form with variables nondimensionalized in a conventional fashion. dU dF_ dG_ fat

We present a model for the steady-state penetration phase of yawed long rods. The projectile-target interaction is comprised of axial deceleration and erosion due to frontal pressure, and lateral deceleration due to cavity expansion pressure. By solving the resulting ODEs through time-stepping, the evolution of the projectile/crater shape is obtained.

It is well known that impact inclination is detrimental to penetration performance for long-rod projectiles into semi-infinite targets. The drop-off in performance, measured as the depth of penetration normalized by the initial projectile length, is generally attributed to interference of the tail of the projectile with the side walls of the penetration cavity. However, little has been done to study the effect of impact inclination on the performance of long rods penetrating finite targets. A reverse ballistic experiment and three-dimensional numerical simulations are used to examine the effect of impact inclination against an oblique plate. In particular, the interaction of the projectile with the plate, to include asymmetric enlargement of the penetration channel and side loading of the projectile, are examined in the simulations, and compared to experimental results.

The loading history for the hypervelocity impact of a long-rod striking a moving flat plate at an oblique angle was analyzed using the EPIC code. The loads were reduced to their axial and lateral components to provide insight into the penetration problem as well as indicate temporal regimes where loading must be considered in the design and analysis of long rod penetrators. Furthermore, the effect of an EPIC input parameter, the erosion strain, used for the numerical treatment of eroding interfaces was assessed with attention focused on the predictions of peak loads, mass loss, and final configuration of the rod.

When a long-rod penetrator impacts a target at a high yaw angle, interference of the penetrator with the sidewall of a crater is the mechanism for the degraded penetration performance. The yawed penetrator is described as a series of cylindrical elements. Using this assumption, the model considers the effective diameters of the penetrator whether or not it interacts with the crater wall and a revised crater profile is calculated with the effective diameters.

Although titanium alloys have been used successfully in aircraft for many years, the relatively high cost of titanium coupled with the limited information on its ballistic properties has prevented widespread use in ground vehicles. In order to provide this ballistic information to vehicle designers, the U.S. Army Research Laboratory (ARL) and the RMI Titanium Company (RMI) performed a joint research program to evaluate the effect of annealing temperature on Ti-6A1-4V alloy, extra-low interstitial (ELI) grade, currently specified by MIL-A-46077D for armor use for the U.S. Army. RMI provided the plates, performed the annealing, and collected mechanical and microstructural information. ARL then tested the plates with the 20-mm fragment-simulating projectile (FSP) in order to determine the response of limit velocity as annealing temperature was varied from 732-1,038 deg C. This report summarizes information presented at ASM International Aeromat '96 Conference in Dayton, OH, in June 1996 and at the 16th International Symposium on Ballistics in San Francisco, CA, in September 1996.

The Cannon-Caliber Electromagnetic Gun (CCEMG) Program is a major effort toward proving the viability of electromagnetic weapons for future use by the Armed Forces. The effort is focused on the successful, system-designed integration of several major components. Crucial to the success of the program are the operational characteristics of the launcher and the integrated launch package (ILP). This paper addresses the launch and flight characteristics, accuracy, and terminal performance of the ILP and subprojectile. The results presented here represent the first known experimental assessment of these parameters obtained from electric gun firings of a tactical flight body over realistic ranges. To date, 39 shots have been fired using a 1.6-MJ capacitor bank located at the U.S. Army Research Laboratory (ARL). A wide variety of instrumentation was incorporated to survey transitional, free-flight, and terminal ballistic regimes from the gun muzzle to target impact 222 m downrange. Free-flight aerodynamic data indicated that the round has adequate in-flight stability. Round-to-round dispersion was computed over a wide range of launch velocities based on downrange impact locations and was used to provide estimates of the dispersion at the design launch velocity of 1,850 m/s. A detailed analysis of the transitional ballistic process has been performed to quantify the various contributors to the total launch disturbance. The results indicated that the sabot/armature discard contributes equally with the aerodynamic jump toward target impact dispersion and increases with launch velocity. For the current launcher configuration, the variability of the discard process Is oriented in the vertical direction. Finally, impact data on armor were limited but nonetheless indicate the round is capable of meeting the CCEMG system requirements.

At projectile velocities exceeding 2000 m/s ablation phenomena due to the heating by air friction may influence flight and impact behavior. Direct in-bore temperature measurements during the flight could clearly improve the theoretical modeling of the heat transfer to hypervelocity projectiles, but the temperature signals must be transmitted from the projectile to the ground station. Since the projectiles are submitted to heavy accelerations, batteries cannot be used as power supply. Therefore, at EMI a low energy telemetry concept is under investigation according to the following principle. At the projectile base a radio frequency reflector with variable reflection coefficient is installed. The reflection coefficient is controlled by an on-board local oscillator, the frequency of which is modulated by the measured signal, e.g., of a temperature sensor. The projectile base is illuminated by an unmodulated fixed frequency ground based radio frequency transmitter, and the signal reflected at the projectile base is picked up by a ground based receiver. The received signal contains the measured signal, shifted by the Doppler frequency, and the Doppler frequency itself. Since controlling the reflection factor of the projectile base only consumes a very low energy, the on-board power supply during the flight phase can be realized by a simple previously charged capacitor. Several telemetry test projectiles of caliber 30 mm have been developed and fired at successively high velocities presently reaching 1850 m/s by the aid of a light gas gun. The actual state of the work and the first results are presented.

An experimental technique is described to launch an intact ``chunk,`` i.e. a 0.3 cm thick by 0.6 cm diameter cylindrical titanium alloy (Ti-6Al-4V) flyer, to 10.2 km/s. The ability to launch fragments having such an aspect ratio is important for hypervelocity impact phenomenology studies. The experimental techniques used to accomplish this launch were similar but not identical to techniques developed for the Sandia HyperVelocity Launcher (HVL). A confined barrel impact is crucial in preventing the two-dimensional effects from dominating the loading response of the projectile chunk. The length to diameter ratio of the metallic chunk that is launched to 10.2 km/s is 0.5 and is an order of magnitude larger than those accomplished using the conventional hypervelocity launcher. The multi-dimensional, finite-difference (finite-volume), hydrodynamic code CTH was used to evaluate and assess the acceleration characteristics i.e., the in-bore ballistics of the chunky projectile launch. A critical analysis of the CTH calculational results led to the final design and the experimental conditions that were used in this study. However, the predicted velocity of the projectile chunk based on CTH calculations was {approximately} 6% lower than the measured velocity of {approximately}10.2 km/S.

Loading the main gun of a battle tank involves repetitive lifting of projectiles stacked at different elevated positions. In this study, we present a biomechanical method to evaluate loader ergonomics for estimating the physiological difficulty. This can be used to improve design and training techniques. A parametric study to evaluate the influence of anthropometry, projectile weight, loading angle and height on the lower back disk compressive force was performed. Comparison between the layout of stack and positions of the round in tank with respect to the loading location and stance was made to reduce the Lifting Index (LI) and help improve loader performance.

By modifying the EPIC-2 hydro-code one can calculate the loading history of an impacting projectile on a target. Loading histories of 20 mm projectiles for impact velocities of 366 m/s, 1012 m/s and 1508 m/s on 914 x 914 mm rolled homogeneous armor plates were calculated with this code. These histories were used in ADINA finite element analyses of the plates. Comparisons of the measured and the calculated plate responses show that hydro-code generated loading histories can be used in finite element analyses of nonperforating ballistic impact.

Firing Table Range Data from Dugway Proving Ground, for the developmental 155mm, M825 Modified Product Improved Smoke Projectile has been reduced and analyzed. Ballistic comparisons between all base versions of the M825 projectile as well as with the M483A1 projectile are discussed. The concept of Ballistic Match/Similitude between two rounds is also expounded upon.

Noise level near military firing ranges must be carefully controlled. To achieve this, one often employs a linear noise propagation model to calculate the noise exposure in the adjacent area. Input for such propagation models are noise levels near the source, usually measured with a microphone. However, it is very expensive to perform measurements for every new weapon under all types of use. This has motivated us to numerically predict the noise levels that serve as input for linear noise propagation models. In this paper, we use numerical simulations to calculate the propagation of the pressure wave close to the muzzle of a weapon. The acceleration of the projectile and the distribution of pressure inside the barrel are calculated using the code IBHVG2 (Interior Ballistic of High Velocity Guns). The end state, calculated by IBHVG2 as the projectile leaves the muzzle, is then used as the initial state for the hydrocode AUTODYN to determine the propagation of the shock wave. The calculated pressure is compared with experimental measurements for an AG3 rifle at a distance of 80 cm from the barrel, and the results correspond well. The method described here applies to weapons of all sizes, from hand guns to artillery guns. The end state of the combined IBHVG2/AUTODYN simulation can be used as input for another code to calculate propagation over a larger distance. The method can also be applied to situations where the blast wave close to a weapon is of interest, e.g. to calculate strain on personnel firing a cannon or effects of firing weapons in confined spaces.

The article entitled “Health and safety at necropsy” by Julian Burton provides a detailed and well written narrative regarding both the risks and hazards faced by professionals during postmortem examinations.1 Despite the presence of a relatively large publication base regarding this topic, important aspects are highlighted, including transmissible spongiform encephalopathies and the more modern, but potentially dangerous, advances in medical technologies. However, we would wish to clarify the issues that the author raises regarding exploding bullets. The difference between a true exploding bullet and a projectile designed to fragment on impact is one of great importance, and one that may cause confusion, as would appear to be the case within this article. Bullets are composed of a casing containing an explosive powder charge, which, on striking, forces the end projectile element out at speeds of up to 1500 metres/second, depending upon the ammunition and the type of gun used. The projectile causes soft tissue damage through crushing, creating a temporary cavity that contains hot gases. The tissue is compressed radially from the centre of the cavity and, depending on its elastic properties, results in tears to structures (as seen with injuries to solid abdominal viscera). The recoil of the tissues, together with …

A VISAR (velocity interferometer system for any reflector) with a new type delay leg is described, which uses multireflection in the etalon for increasing the delay time τ. When the incident angle is changed, the sensitivity of the VISAR can be changed. A few step values of the sensitivities can be selected for different applications. Experimental results for measuring the bullet’s motion in the 7.62‐mm gun are presented.

This note describes three demonstrations that can be used to introduce projectile motion. They are simple to conduct, are fun for the students, and require their participation at all stages. There is no lack of student volunteers for these demonstrations.

Introduction. Physical Basics of Wound Ballistics. Preliminary Remarks. Frames of Reference and Systems of Units, Notation. Mechanics. Kinematics. Mass, linear momentum, force. Work and energy. Circular motion. The laws of conservation. Equations of motion. Fluid Dynamics. General. Thermodynamic principles. Material properties. Inviscid flows. Viscid flows. Jets. Measurement Techniques. General. Dynamic processes. Physical quantities. Measurement technique to detect the development of rapidly changing pressures. Historical Background and International Treaties. The Development of Small Arms. General. The development of ammunition. The development of small arms. The twentieth century. International treaties. Early Developments in Wound Ballistics. Ammunition and Arms, Ballistics. General. Ammunition. The different parts of a cartridge. Ammunition. Recent developments of ammunition. Firearms. Composition and classification of firearms. Hand guns. Rifles. Ballistics. General. Interior ballistics. Processes at the muzzle. Exterior ballistics. Stability and tractability. General Wound Ballistics. General. Preliminary remarks. What does a human being die of after being hit? Possible causes of death. Definition of various energy quantities, their derivation and relationship. Processes in the Shooting Channel (Especially the Temporary Cavity). General. Behaviour of projectiles in a dense medium. Phenomenology of the temporary cavity. Quantitative description of the temporary cavity. Instability of a projectile in a dense medium and the consequences on the temporary cavity. Sectional density influence on the shape of the temporary cavity. The behaviour of different projectiles designs in a target medium. On the sterility of projectiles. Tissue Simulants. General. Gelatine. Soap. Comparison: soap-gelatine. Tissue simulant for bones. Other Simulation Methods. Corpses. Experiments on animals. Mathematical models, computer models. Cell cultures. Wound Ballistics of Handgun Ammunition. Penetration Depth and Perforation Capacity of Projectiles in Gelatine, Soap, Muscle Tissue and Bones. General theory. Penetration depth in gelatine, soap and muscle tissue. Penetration capacity in bones. Threshold velocities of the eye. On the Effectiveness of Projectiles. General. Criteria of effectiveness. Measured values for energy release of projectiles in gelatine. Is it possible to establish a general criterion of the effect? Special Projectiles. General. Non-penetrating projectiles. Projectiles with Extraordinary ballistics qualities. Fluid jets and gas jets as projectiles. Wound Ballistics of Rifle Ammunition. General. Remote Effects. General. Shock waves. Pressure waves in blood vessels. Bone fractures in the vicinity of the shooting channel. Debridement. General. The relationship between the size of the temporary cavity and the amount of devitalized tissue. Determination of the Effectiveness of Rifle Bullets and Fragments - Casualty Criterion. General. Casualty criterion. Bases for the Formulation of Future International Treaties. Disadvantages in the wording of existing treaties. Methods of judgement independent of the type of projectile. Possibilities of standardization. Tables. Index of Tables Previously Presented in this Book. Conversion Tables. Lengths. Velocity. Mass units. Force. Pressure. Energy and work. Temperature. Material Properties. Fluids and fluidal substances. Solid substances. Caliber Designations. Caliber designation metric units. Caliber designation US units. Ballistics Data of Ammunition. Ballistics data metric units. Ballistics data US units. Projectile Designations. Projectile shape. Projectile material. Projectile construction. Geometrical Data of Some Particular Projectiles. Military projectiles. Additional projectiles. Twists Lengths, Twist Angles and Number of Revolutions.Pistols and revolvers. Rifles. Firing Tables. Pistols and revolvers. Rifles. Signal and illumination ammunition. Shotgun Calibers and Shot Pellets. Calibers of shot barrels. Ballistics properties of shot pellets. Designation of buck shot sizes. Designation of normal shot sizes (Anglo-American system). Designation of normal shot sizes (metric system). Glossary. English-German-French. German-English-French. French-German-English. Literature. Bibliography. References. Illustration References. Index.

For continuous recording of projectile motion in a gas gun, a new method, “inline holographic velocimetry”, is proposed and demonstrated. The inline hologram pattern of a wire is recorded by a streak camera via a mirror, which ismovingbetween the wire and the recording plane. The mirror is glued onto the nose of an accelerating projectile. The projectile motion can be obtained precisely by analyzing the fringe spacings which gradually become narrower with increasing displacement. It was found that the projectile acceleration is almost constant except in the early stage.

Recently marketed PMC (Pan Metal Corporation) Ultramag tubular hollow point ammunition is uniquely constructed with a two-part projectile composed of a tubular copper bullet and a Teflon wad. A fatal gunshot wound with this ammunition is described. A unique radiographic pattern and the results of test firing are also presented.

An electromagnetic (EM) railgun launcher facility has been developed to routinely conduct hypervelocity impact tests. Two types of completely reusable EM launchers have launched sabot/impactor packages between 2 and 43 grams to velocities between 1.5 and 8.5 km/s. The highly reliable railguns have conducted over 250 projectile launchings and have established a projectile/launcer data base covering interior as well as exterior ballistic considerations. A conventional type instrumented ballistics range is compatible with the EM launcher and can be used to conduct anti-armor and lethality experiments at hypervelocities.

LTV Aerospace and Defense Company (LTVAD) using the company's highly reliable, reusable electromagnetic (EM) railguns have conducted over 200 projectile launchings since the second Electromagnetic Launch Technology Symposium and have established a projectile/launcher data base covering interior as well as exterior ballistic considerations. Projectiles weighing 2 to 43 grams have been launched with the LTVAD EM launcher lab's 12.7 and 20 mm railguns over the velocity range of 1.5 to 8.5 km/sec. This paper describes the interface and compatibility relationship between an EM launcher and the launch package during the interior ballistics of launch and the influence on the subsequent exterior ballistics. Some terminal effects and test descriptions conducted at LTVAD are presented along with associated projectile monitoring instrumentation utilized in determining projectile motion, integrity, orientation, flight characteristics, and impact phenomenology. This work was sponsored by the Army Ballistic Missile Advanced Technology Center.