Bullet Trajectory Research Articles

AK bullet (7.62×39mm) holes on 1-mm sheet metal: A forensic-related study in aid of bullet trajectory reconstruction.

Bullet holes play a major role in the trajectory determination of fired bullets, potentially suggesting where the shots were fired from. Few methods are currently employed to estimate the angles of incidence of fired bullets using bullet holes. The literature has stressed that knowledge about the impact behavior of the specific bullet-substrate interfaces, including the most viable method for estimating the angle of incidence of that combination, requires empirical testing to enable successful analysis. The perforating bullet hole characteristics of AK bullets fired into 1-mm sheet metal over a range of angles of incidence have been documented in this study to aid bullet trajectory determination. A strong inverse relationship has been demonstrated between particular impact mark dimensions and the angles of incidence, revealing the possibility of using these dimensions to predict the angles of incidence for AK bullets perforating 1-mm sheet metal in actual crime scenes. This study has further confirmed the existence of a recently reported phenomenon for impacts related to this projectile-substrate combination, the "double-headed impact mark," and relationships with the angles of incidence of fired AK bullets. While suggesting an alternative and confirmative new method to understand the angles of incidence of fired AK bullets in 1-mm sheet metal using measured bullet defects, the study highlights a complex deviation phenomenon and a potential error that could occur when determining bullet trajectories using probing, stringing, or laser methods for the impact conditions described.

Ricochet of AK bullets (7,62 × 39 mm) on concrete and cement surfaces; a forensic-based study

The ricochet behaviour of AK bullets (7,62 x 39 mm) on two different concrete samples (rough and a cement-skimmed intermediate) and one cement sample were explored in this study. The estimated critical angles for these surfaces were shown to be 10.8° and 11.1° for the rough and intermediate concrete surfaces and 13.2° for the cement surfaces. In all occasions, fragmentation of the bullets was observed upon reaching critical angles. The results from the concrete surfaces highlighted the sensitivity of AK bullet ricochet angles from concrete surfaces with a different surface roughness and composition. Almost all resulting ricochet angles for the more frangible cement surfaces were observed to be much higher than currently reported literature would suggest. Consistent bullet wipe markings were observed on most samples, acting as a strong indicator for the directionality of the projectile during ricochet. Interestingly for the cement surface, a clear relationship was reported between the angle of incidence and the depth of the crater produced. Ultimately, this study highlights the potential uncertainties and possible errors that could occur in bullet trajectory determination from ricochet marks for this bullet and target combination if theoretic interpretations alone are used. There is no substitute for bullet and surfacespecific practical trials if the most accurate shooting scene reconstructions are to be carried out.

How to put quantum particles on magic bullet trajectories that can hit two targets without a clear line-of-sight

Quantum particles move in strange ways, even when they propagate freely in space. As a result of the uncertainty principle, it is not possible to control the initial conditions of particle emission in such a way that the particle will definitely pass through two precisely defined positions along its path, even if it is possible to line up the two positions with the emitter. However, there is also an upside to the quantum mechanical laws of motion: constructive quantum interferences can actually raise probabilities to values higher than those permitted by classical causality. Here, it is shown that conventional interferometric methods can be used to prepare photons in a quantum state in which a non-vanishing fraction of particles will hit both of two possible targets, even though the direct line-of-sight connecting the two targets is blocked at the source. The demonstration of the effect is complicated by the uncertainty principle because the physical detection of a particle at one target disturbs the motion of the particle, making it impossible to determine whether the initial state of motion would have allowed the particle to hit the other target or not. It is nonetheless possible to determine the minimal fraction of “magic bullet” particles that must have hit both targets by showing that the number of particles hitting target A is larger than the number of particles missing target B. Quantum interference effects can thus be used to optimize the path of particles in free space beyond the classical limit of motion along a straight line.

The value of simplicity: externally validating the Baylor cranial gunshot wound prognosis score.

Gunshot wounds to the head (GSWH) are devastating injuries with a grim prognosis. Several prognostic scores have been created to estimate mortality and functional outcome, including the so-called Baylor score, an uncomplicated scoring method based on bullet trajectory, patient age, and neurological status on admission. This study aimed to validate the Baylor score within a temporally, institutionally, and geographically distinct patient population. Data were obtained from the trauma registry at a level I trauma center in the southeastern US. Patients with a GSWH in which dural penetration occurred were identified from data collected between January 1, 2009, and June 30, 2019. Patient demographics, medical history, bullet trajectory, intent of GSWH (e.g., suicide), admission vital signs, Glasgow Coma Scale score, pupillary response, laboratory studies, and imaging reports were collected. The Baylor score was calculated directly by using its clinical components. The ability of the Baylor score to predict mortality and good functional outcome (Glasgow Outcome Scale score 4 or 5) was assessed using the receiver operating characteristic curve and the area under the curve (AUC) as a measure of performance. A total of 297 patients met inclusion criteria (mean age 38.0 [SD 15.7] years, 73.4% White, 85.2% male). A total of 205 (69.0%) patients died, whereas 69 (23.2%) patients had good functional outcome. Overall, the Baylor score showed excellent discrimination of mortality (AUC = 0.88) and good functional outcome (AUC = 0.90). Baylor scores of 3-5 underestimated mortality. Baylor scores of 0, 1, and 2 underestimated good functional outcome. The Baylor score is an accurate and easy-to-use prognostic scoring tool that demonstrated relatively stable performance in a distinct cohort between 2009 and 2019. In the current era of trauma management, providers may continue to use the score at the point of admission to guide family counseling and to direct investment of healthcare resources.

Anatomical distribution and autopsy features of gunshot injuries to support the manner of death

The autopsy features of gunshot wounds can be useful in understanding the manner of death. This research aims to provide concrete data to help to discriminate between homicide and suicide based on specific autopsy findings.A search of the database of the Cook County Medical Examiner's Office from August 2014 through April 2019 identified 3491 deaths due to gunshot wounds. Deaths due to complication from delayed fatal gunshot wounds, subjects who received hospital care prior to death, and decomposed bodies were identified and excluded. The following data were recorded: manner of death, demographic data, firearm and bullet type, number and location of gunshot wounds, range of fire, toxicology, and additional injuries. The study primary focused on the analysis of the bullet trajectory. A course leftward-upward-backward was the most frequent observed trajectory in suicides; a course rightward-upward-frontward was the most frequent observed trajectory in homicides.When the internal trajectory of a bullet is interpreted in the light of all available evidence it can impeach or corroborate witness statements and highlight consistencies as well inconsistencies in investigative reports and scene examinations.

Atypical Gunshot Injury Traversing the Neck with an Unexpected Nonlinear Bullet Trajectory: a Case Report and Review of the Literature

Gunshot injuries involving the head and neck region yield profound morbidity and mortality rates. Projectile-related factors comprising various physical and dynamic properties of a bullet, as well as tissue-related factors, determine the disruptive effects of projectiles on living tissues. We experienced an extremely unusual case of a gunshot injury to the neck, wherein the bullet transversely penetrated across the deep neck structures to the contralateral side of the shoulder without damaging any vital organs. A 51-year-old man presented with a gunshot wound to the neck from a point-blank range. A bullet entry hole was observed on the left side of the neck without an exit hole; however, the patient was conscious, vital signs were normal, and no active bleeding, cranial nerve palsy, or aero-digestive tract injury was found. Imaging tests revealed a bullet lying in front of the right humeral head, which was extracted by emergency surgery. The patient was uneventfully discharged. According to the localization of the damaged tissues and the positional relationship between the bullet’s entrance and its destination, the bullet was estimated to have nonlinearly traversed the neck by traveling through the interstructural spaces associated with the least tissue resistance. Our experience strongly suggests the importance of realizing the unpredictable nature of a bullet trajectory in a body. An appropriate understanding of various ballistic factors and wounding mechanisms can be of great help in the adequate assessment and management of patients with gunshot injuries.

Tubular Opacity in the Lung Along a Bullet Trajectory

Tubular Opacity in the Lung Along a Bullet Trajectory

Preliminary Comparative Investigations on Ballistic Properties of Intermediate Cartridges

The preliminary results of comparative investigations on intermediate cartridges were presented in this paper. The research focused mainly on the adopted assumptions and verification of research methods. Pressure ballistic test barrels, manufactured according to NATO EPVAT standards, were used for tests. The pressure courses of propellant gases in the barrel and the projectile velocity at four points of the bullet trajectory were measured. The pressure impulses, R100 parameter at 50 m and average bullet drag coefficient were calculated for each type of cartridge. The results allowed for a preliminary ballistic comparison of the most popular types of intermediate cartridges.

The Bullet Shockwave-Based Real-Time Sniper Sound Source Localization

Real-time sniper sound source localization in a real environment has long been an important research topic in the acoustic field. All those positioning systems utilize the Muzzle Blast signal for positioning. Acquiring a low signal to noise ratio Muzzle Blast signal is the most effected issue in the unfavorable situations. Detecting the Shockwave signal in the real environment is easier due to its higher signal to noise ratio value and some other its specific features. This paper focuses on the designing of a system that deals with the sniper positioning based on using only bullet Shockwave signals. The first acquired Shockwave signal in the microphones’ array is not from the fired bullet and specifies only the relevant point on the bullet trajectory. Hence, in this research, by utilizing the two least microphones count arrays in the 2-Dimensional real environment, first it is obtained the bullet trajectory, and then in an initiative, the reduction curve of the Mach number on this bullet trajectory, is devoted to locating the source of the fire. Also, the generalized cross-correlation phase transform method is used for calculating of the time delays between the microphones in an array. Based on the proposed method, the experimental results demonstrate the sniper locating with a precision of less than 30 meter at the distance of 400 meter, using an AK_47 weapon and a 6.72 millimeter caliber in different real environmental situations.

Gunshot injury to the upper limb with an unusual bullet trajectory

Gunshot injuries are not common in European Union countries, although the trend is observed to increase their number over the years [1]. Firearm injuries to the upper extremity are very uncommon. The results of a Swedish study from an urban major trauma center showed only 3 cases of this injury location in a 73 total gunshot wounds treated in one year; the lower extremity was the most commonly involved [1]. If they occur, they are usually the result of accidental shots from hunting rifles, less commonly from police guns or as a result of criminal encounters. As the size of the upper extremity is not great (compared to, e. g. the trunk), the vast majority of these wounds are penetrative by character, with clearly visible entry and exit parts. The spectrum of tissue damage is usually complex, including bone fractures, vessel, nerve, tendon and muscle injuries. Treatment of gunshot wounds may be challenging, particularly if they require reconstruction of several structures [2], [3], [4]. Sometimes complex repairs may be not possible due to tissue defects and the risk of infection. We report the case of a gunshot wound involving the right forearm, arm and shoulder, running along the axis of the upper limb. The entry wound was located in the middle forearm, the trajectory ran along the whole arm and ended at the right clavicle, very close to the axillary artery, where the bullet was found. In spite of such a long distance travelled, the bullet wounded only the brachial artery in the cubital fossa.

Life-Saving Silicone Breast Implant After Firearm Injury: Case Report and Treatment Recommendations

Breast augmentation with silicone implants is one of the most commonly performed operations by plastic surgeons. Here, we report a case of a 30-year-old female patient with a ballistic injury to bilateral breast implants, where the silicone implant was likely responsible for deflecting the bullets trajectory and saving the women’s life. Ballistics analysis of bullet trajectory was performed with high-resolution computed tomography scan analysis. Operative management was implant removal, pocket irrigation, and a short course of antibiotics. A literature review was performed on all previously published breast implant–related firearm injuries. The authors advise operative management with implant removal and delay of replantation for minimum 6 months’ time.

A Methodology for the Zoning Danger Region in Small Arm Firing Range Using Aerial Photogrammetry with Drone

During firing exercises in the military forces, safety accidents have occurred and caused nonbattle loss of human lives. Despite huge impact of the safety accidents in firing ranges on the military forces and civilians, the preventive measures have been limited and inflexible. In this study, to decrease the accident rate in small arm firing ranges, a methodology was presented to determine danger zones in firing ranges that resulted from direct bullets or ricochets during firing exercises. On the basis of ballistic theory and the actual terrain data surveyed by a drone, the danger zone of OO Firing Range was identified by schematizing the trajectories of the direct bullets and ricochets. The Monte Carlo simulation (MCS) with the accuracy of the small arm on the terrain data showed that the danger zone of the current firing range was limited due to topographic advantages. However, when human errors were included in the MCS, the danger zones were significantly enlarged. The methodology of the present study can provide a safety check‐up model that identifies danger zones in the firing ranges used by the Army.

The application of the ballistic pendulum for the bullets velocity measurements

The accurate values of the initial velocity of bullets are significant for the quality and precision of small arms. The application of the simple measurement methods, during the tests of the weapon and ammunition, enables the determination of the velocity values from the group of shoots. The accuracy of bullet trajectory, appropriate trajectory correction parameters and terminal ballistics parameters are depended of the quality of initial conditions as initial velocity. The ballistic pendulum, as simple and old-design device, enhanced with optoelectronic encoder sensor and computer acquisition system, can be one of the good start-up device platform for measurement of velocity and observation of the terminal ballistics effects. The function principle of the considered device is based on the energy conservation. Initial data are mass of bullet, mass and dimension of pendulum, and result is velocity, according to the values of time and angle of pendulum. The output signals of measured angle in time are captured, and as required values for calculation the velocity on the microprocessor platform, for each shoot in the test group. The microprocessor platform saves measured and calculated values in memory and generates statistic report of results. The presented method can improve weapon and ammunition tests, by decreasing the time of measurement acquisition and increasing the quality and speed of results without errors. The method and system is simple and low-cost, and enables the design of small arms ammunition database of testing results.

Meta-Analysis of Functional Outcomes in 5508 Patients Sustaining a Gunshot Wound to the Head

Abstract INTRODUCTION There is currently no consensus regarding prognosis and management for gunshot wounds to the head (GSWH). To the author’' knowledge, this is the first meta-analysis to study functional outcomes in GSWH. METHODS Five online databases and the reference lists of relevant articles were queried for cohort studies of GSWH reporting factors associated with functional outcome. PRISMA guidelines were followed. Study quality was assessed using the Newcastle–Ottawa scale. Glasgow Outcome Scale (GOS) outcomes were divided into unfavorable (GOS 1-3) and favorable (GOS 4-5). Pooled estimates of odds ratios and 95% confidence intervals were derived using random-effects models. Heterogeneity was assessed with I-square and meta-regression. Funnel-plots were utilized to assess publication bias. RESULTS We identified 35 retrospective cohort studies encompassing 5508 GSWH patients. Out of the factors assessed, the ones significantly associated with unfavorable functional outcome were: postresuscitation GCS 3 to 8 (Odds Ratio 33.2, 95% Confidence Interval [10.1-108.6]), suicide attempt (3.6 [1.7-7.8]), penetration of the dura (10.3 [1.8-60.5]), bullet trajectory through both hemispheres (8.3 [4.1-17.2]), through the ventricles (8.8 [1.6-48.8]), and through multiple lobes (8.6 [2.2-33.5]). No statistical significance was found for unfavorable functional outcome regarding patient age, sex, pupillary response, and the existence of an exit wound. CONCLUSION This is the first systematic review and meta-analysis regarding prognostic factors for neurologic outcomes in patients sustaining GSWH. Such factors can inform clinical decision-making and assist in setting patient and physician expectations in the acute setting. Further research is required to properly incorporate this information into management guidelines.

Accuracy and Reproducibility of Bullet Trajectories in FARO Zone 3D.

With three-dimensional (3D) laser scanning technology and software packages, the practice of documenting and measuring bullet trajectories has benefited from greater accuracy and reproducibility. This study investigated the accuracy and reproducibility of the bullet trajectory tools in the software package, FARO Zone 3D (FZ3D). Twelve participants were provided laser scanner data for 21 bullet trajectories on drywall panels with impact angles between 25° and 90°. When the impact plane was manually aligned by the operator, 75% of the absolute errors were within 0.91° and 0.98° for the azimuth and vertical angles, respectively. The vertical angle improved to 0.47° when impact plane alignment was taken with respect to gravity (no operator influence). Thus, manual alignment is shown to be subject to greater error than alignment with gravity. However, this study shows that the accuracy and reproducibility of the FZ3D bullet trajectory tools to be comparable with previous research studies.

Experimental measurement of the bullet trajectory after perforation of a chambered window

AbstractThe assessment of the failure and final response for glass structures loaded by high‐speed events such as blast or projectile loading are challenging tasks for researchers. For many studies, knowledge about the strain rate effect in brittle materials and well described finite element simulations are not enough to reach a correct outcome. For that reason, only experimental assessments can give credible results. Moreover, the impacting glass fragments or projectiles often change the angle of the trajectory after perforation of a target. In this study, the authors present the change in the 3000 J military bullet trajectory after total penetration of a two‐chambered civil engineering facade window. A series of actual tests were performed for different angles of the soda‐lime float glass specimen that were subjected to bullet impact. The results obtained chambered windows given an understanding of the behavior of the separate glass surfaces under such complex scenarios. Furthermore, the presented tests support the designers and military shooters by the assessment methodology of projectile bullet trajectory change as a function of the incident angle.

Outcome and rational management of civilian gunshot injuries to the brain\u2014retrospective analysis of patients treated at the Helsinki University Hospital from 2000 to 2012

BackgroundTreatment of gunshot wounds of the brain (GSWB) remains controversial and there is high variation in reported survival rates (from < 10 to > 90%) depending on the etiology and country. We retrospectively analyzed the outcome of a series of consecutive GSWB patients admitted alive to a level 1 trauma center in a safe high-income welfare country with a low rate of homicidal gun violence.MethodsPatients admitted due to a GSWB to the HUS Helsinki University Hospital during 2000–2012 were identified from hospital discharge registry and log books of the emergency room and ICU. CT scans and medical records of these patients were reviewed. Univariate analysis and backward logistic regression were performed, and their results compared with that of a systematic literature review of factors related to the outcome of GSWB patients.ResultsSixty-four patients admitted alive after GSWB were identified. Eighty percent had self-inflicted GSWB, 81% were contact shots, and 70% were caused by handguns. In-hospital mortality was 72%. Factors associated with mortality in our series were low GCS (≤ 8) at admission, transventricular bullet trajectory, and associated damage to deep brain structures, as reported before in the literature. Of the 64 patients admitted alive, 42% (27/64) were admitted to ICU, 34% (22/64) underwent surgery, and in 25% (16/64), craniotomy and hematoma evacuation was performed. Mortality in the surgically treated group was 32% but near 100% without surgery and ICU treatment. Median GOS in the surgically treated patients was 3 (range 1–5).ConclusionsGSWB caused by contact shot from handguns has a high mortality rate, but can be survived with reasonable outcome if limited to lobar injury without significant damage to deep brain structures or brain stem. In such GSWB patients, initial aggressive resuscitation, ICU admission, and surgery seem indicated.

Dispersion Analysis of Rounds Fired from a Glauberyt Machine Pistol

Within an enclosed shooting range of the EMJOT company, the process of firing one hundred single bullets from a Glauberyt machine pistol was recorded. The empirical test used 9x19 mm FMJ Luger (Parabellum) ammunition manufactured in the Czech Republic in 2017. As the weapon is dedicated to special forces, the shots were fired by an anti-terrorist operative, at a target located 25 m away. In order to determine bullet dispersion, the results of the experiment were subjected to statistical processing. Mean displacement and mean square displacement relative to the mean hit point, histograms, normal distribution, as well as statistical tests and hypotheses were used for estimation. The shots were recorded with a high speed digital camera Phantom v 9.1. The videos recorded were used to determine the initial kinematic parameters of the bullet trajectory.

Lead and copper in hunted wild boars and radiographic evaluation of bullet fragmentation between ammunitions

ABSTRACTThe purpose of the present study was to evaluate the content of lead in carcasses of wild boars shot with lead bullets, in comparison with that of copper caused by lead-free ammunitions. Radiographic images of hunted boars were obtained in order to assess the degree of bullet fragmentation in the carcasses. Samples of meat were collected from different body areas at increasing distance from bullet trajectory, to be analysed by ICP-MS for lead and copper levels. In wild boars shot with lead ammunitions, a massive dispersion of bullet fragments and very high lead levels were detected. By contrast, in wild boars killed with copper ammunitions no radiographic signs of bullet fragmentation were observed. Copper ammunitions seem therefore a safer alternative to standard lead-core ones, due to their minimal fragmentation and the relatively low toxicity of this metal.

Auditory risk of exposure to ballistic N-waves from bullets

Objective: Assessment of the auditory risk associated with sound from ballistic N-waves produced by a rifle bullet.Design: Acoustical recordings of ballistic N-waves passing through a microphone array at 6.4 metres down range were analysed to determine (a) the trajectory of the bullet, (b) the distance between the trajectory and each microphone (less than 1.3 m), and (c) the numbers of permissible exposures according to both damage-risk criteria for impulsive noise in the current U.S. military standard (MIL-STD-1474E).Study Sample: The gun was an AR-15 style semiautomatic rifle configured to fire a 0.50 calibre Beowulf00AE cartridge. Four sample shots were recorded for each of four microphone spacing conditions and five kinds of ammunition (80 shots in total).Results: The ballistic N-waves recorded in this study would constitute a significant auditory risk to unprotected listeners at all distances sampled. The numbers of permissible exposures decreased as the distance to the bullet trajectory decreased, decreased with increased bullet length, and departed from linear increases as the bullet velocity increased.Conclusions: Unprotected exposure to a ballistic N-wave from a supersonic 0.50 calibre bullet presents a significant risk to hearing at distances of 6.4 metres down range and through trajectories within 1.2 metres of an ear.