Pellet embolization to the right atrium following double shotgun injury

A 28-year-old man sustained two shotgun injuries of the left inguinal region from a distance of about 1.5 m by simultaneous discharge of both shells from a sawn-off double-barrelled 16-bore shotgun (diameter of the lead pellets, 4 mm). The first X-ray examination carried out soon after hospital admission showed a single embolized pellet near the right margin of the cardiac silhouette. Eight months later, the man committed suicide by drug intoxication. At autopsy, the embolized pellet was found embedded between the pectinate muscles of the right atrium. On the basis of the reported case and with reference to the pertinent literature, the paper points out the medico-legal aspects of venous bullet/pellet embolism and the risk of lead poisoning after shotgun injury.     

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.     

The effects of various intermediate targets on dispersion of shotgun patterns.

Intermediate targets cause dispersion of a shot pattern by a ricochet effect. Thus, the intermediate target must have sufficient thickness or tensile strength to slow down the initial group of shot striking the target. Aluminum and steel screen, ordinary window glass, thin cardboard and thin cowhide did not manifest these qualities under the conditions of these experiments.     

Pump-gun as a weapon. Type of injuries, prohibition of weapons

Pumpguns are shotguns with pump action whose injuries and wound mechanisms have several special features: extremely high kinetic energy of the shot (2500 to 3500 J) frequent cases of "Kr?nlein shots" (exenteration of the brain) punchmark/imprint immediately adjacent to the entrance wound from the front of the pipe magazine exit wounds from buckshot may be similar to pellet entrance injuries from a distant shotgun discharge the use of various shotgun cartridges (plastic ammunition, slug bullet, various lead pellets) within the same weapon. The change in the Austrian gun law and the banning of the pumpgun in 1995 is also discussed in the article.     

Maximum range of pellets fired from a shotgun

A mathematical model to determine the maximum range of pellets fired from a shotgun has been suggested. It has been assumed that the air resistance experienced by a pellet is proportional to the square of its velocity (?μV²) where $\text{μ =}\text{A}\text{C}$ with

$\text{C=0.061}\text{86}\text{N}{}^{\mathrm{<mtext>1</mtext><mtext>3</mtext>}}$

and

$\text{A=}\text{1}\text{[17 696+2N+10 000(0.2?d)]}$

N is the number of pellets/ounce and d is the diameter of the pellets in inches. A method for calculating the maximum range has been suggested, and the values obtained for Buck 00, size 8 and size 9 American pellets are very close to the reported experimental observations. The maximum ranges for other sizes of pellets have also been calculated. The angle of projection decreases with increase in velocity and increases with increase in the weight of the pellet. It varies between 26° to 32° for common sizes of pellets and standard shotgun velocity. The maximum range in air is only 1 – 3% of the range attained by a pellet in vacuum.     

Shot range estimation based on pellet distribution in shots with a pump-action shotgun

In the present study, shots from different ranges were fired using a non-choked pump-action shotgun (Hugsan) of calibre 12 with a bore length of 52cm and pellets of various sizes. The aim of the study is range estimation from the distribution of pellets.Using pellets of 2, 3.5, 5 and 8mm size, 5 shots were fired from: 0.7, 0.8, 0.9, 1, 2, 3, 5, 10, 15, 20 and 25ms. The maximum distance between the pellets in vertical and horizontal direction was measured. Statistical evaluation of the data revealed a highly significant correlation for each pellet type; the constant values a and b were calculated to be used in the linear regression equation y=a+bx.As a conclusion, the linear regression equation as well as table data may allow range determination within acceptable ranges of error for the same barrel length and diameter for the same cartridge type. Under identical conditions they may also provide information for pellets of comparable size.     

根据霰弹丸分布图形推断射击距离的实验研究

目的 建立推断制式霰弹猎枪射击距离的数学计算公式和方法。方法 选用国产制式12号及16号猎枪,配用1号及3号猎枪弹,以1至12m距离射击实验靶纸,获得霰弹分布图形360例,将图形测量数据与实验距离进行数学理论分析。结果 建立6种不同枪弹种类推断射击距离d的计算公式,分别为12-1型(缩口)ss=-0.2+0.44d;12-1型(无缩口)ss=-0.94+0.63d;12-3型(缩口)ss=-0.59+0.52d;12-3型(无缩口)ss=-0.36+0.34d;16-1型s=-0.37+0.30d;16-3型s=-0.16+0.23d,并用Visual Basic5.0软件编制通用程序汇总软件。结论 本研究建立的方法简单实用,误差较小,可以用于推断制式猎枪的射击距离。     

An investigation into pellet dispersion ballistics.

Existing works on pellet dispersion ballistics are confined to some data-based models derived from statistical analysis of observed patterns on targets but the underlying process causing the dispersion lacks due attention. The present article delves into the relatively unexplored areas of dispersion phenomena, and attempts to develop a theoretical model for general application. The radial velocity distribution of pellets has been worked out by probing into the physical process of dispersion based on transfer of momentum from undispersed shot mass to dispersed pellets. The ratio 2u/v0 (u = root mean square (r.m.s.) radial velocity and v0 = muzzle velocity of the pellets) is found to be fairly constant for a fixed gun-ammunition combination and has been suitably designated as 'Dispersion Index' (DI) characterising its dispersion capability. The present model adequately accounts for pellet distribution on targets and it appears that 'Effective Shot Dispersion' (ESD) as introduced by Mattoo and Nabar [ESD = [(4/N0)sigma Ri2]1/2, where N(0) is the total number of pellets and Ri is the radial distance of the i-th pellet from centre of pattern], gives a faithful numerical measure of overall dispersion at a given distance. A relationship between ESD and firing distance, incorporating the effects of air resistance and gravity has been worked out, which reveals that DI controls the dispersion at a given distance. For small distances (less than 20 m) the relation reduces to a linear one, as already observed empirically and looks like ESD = E0+DI x firing distance, E0 being a parameter dependent on gun and ammunition. The present model, unlike earlier ones, is versatile enough to explain the natures of the dependence of dispersion on firing distance as well as on gun-ammunition parameters, which are essential for a faithful reconstruction of a crime scene. The model has been tested with such experimental data as are available and reasonable agreement is observed.     

Firing distance estimates with pellet dispersion from shotgun with various chokes: an experimental, comparative study

There are several studies suggesting models for firing distance estimation due to pellet dispersion, but few of them consider the degree of choke of a shotgun. The purpose of this research is to suggest some models for estimation of the firing distance for choked and cylinder bore shotguns. Twelve gauge with full chokes, and 12 and 16 gauge with cylinder bore shotguns were fired with #2 and #5 shots from 75, 100, 300, 500, and 1000 cm distances. Statistically significant pellet dispersion values were found for each shotgun by using #2 and #5 shots for different firing distances. All the data obtained were analyzed with linear regression and four models were constituted. Investigators should use special formulae for each shotgun, degree of choke, and pellet type while determining the firing distance. Therefore, more experimental and comparative studies should be designed for each type.     

The Difficulties in Assessing Wounds Created by .410 Bore Ammunition and Weapons

When interpreting firearm injuries, the distinction between gunshot wounds and shotgun wounds is important, and separation of these categories is typically straightforward. However, .410 bore firearms can make the classification difficult. Shotguns and revolvers that can fire the same .410 bore ammunition are readily available. This study investigates the soot and gunpowder deposits and pellet patterning of these two types of weapons using cartridges specially designed for .410 bore revolvers and standard birdshot pellet ammunition. For both ammunition types, the revolver had more prompt pellet dispersion and positive detection of gunpowder at greater distances compared to the shotgun. Additionally, .410 bore slugs are of similar caliber to many common bullets. In comparing the .410 bore slugs to equivalent bullets, some morphologic differences may be imparted on the skin by the slugs, but the greatest insight into the weapon remained with the retained projectiles.     

Case report of a homicide by a shotgun loaded with unusual ammunition

Reported is the case of a man killed by a neighbor with a shotgun loaded with a unusual ammunition. The cartridge contained several shots chained together by metallic wires. Such ammunition has been used for hunting purposes but is now banned, so it can be handmade only. The joined pellets produce a wound with features that are different from those of a wound made by a regular load of pellets. Several interpretive problems are caused by the unknown number of pellets contained in the shell and the effects of the wire holding the shot together.     

.177 caliber pellet classification system and identification key

A classification system and identification key for .177 caliber air gun pellets was developed based on a five-class characteristic criterion. Sixty-eight pellet types from 15 companies were examined and compared. A classification system was developed based on the pellets' head shapes, skirt types, lengths, weights, and other markings or observations. In some cases, when a pellet is recovered from a crime scene, product brand identification may aid the investigation. Even though all product brands cannot be identified, various brands of pellets can be eliminated based on a pellet's class characteristics. The pellet producers in this study were located in the following countries: China, Czech Republic, England, Korea, Spain, and the United States. An identification key can be used for possible pellet identification or elimination.     

跳弹创形态学的实验研究

目的 探讨跳弹创形成的条件,研究跳弹在体内弹道学特点及致伤能力,建立跳弹创的诊断依据。方法选用国产54式手枪及56式半自动步枪,配用51式手枪弹及56式步枪弹以水磨石板为反跳靶体,射击约克夏种猪4头,复制出跳弹创模型12例。观察射入口、创道及着弹点特征。结果 跳弹的形成受靶体性状、弹头形态和速度、入射角与反跳角等条件因素的影响;在相同条件下高初速尖型弹头的反跳角<低初速圆型弹头;创道无明显瞬时空腔效应;根据实验结果建立了6项诊断依据。结论 正确诊断跳弹创对射击方向和距离、重建弹道、分析枪击目的、评估损伤程度有实用价值。     

Pseudo-gunpowder stippling caused by fragmentation of a plated bullet

In this report we present a case of pseudo-gunpowder stippling caused by fragmentation of a plated bullet. Investigation of the incident revealed absence of an interposed target, no evidence of ricochet, and a normally functioning, undamaged weapon. Electroplated ("plated" or "coated") bullets are relatively uncommon. They look similar to jacketed bullets in that the lead core is covered by a copper-colored jacketlike material. However, the copper-colored plating material is thinner than the typical jacket material. In certain instances, the plating may strip away from the lead core during transit through the barrel of the weapon and can produce injuries that mimic gunpowder stippling. Forensic pathologists are advised to be aware of this phenomenon. Misinterpretation of such wounds could result in improper classification of range of fire or improper conclusions about the presence or absence of an interposed target or ricochet.     

Ballistic characterization of the Remington Premier Copper Solid sabot shotgun slug

We evaluated the impact and penetration characteristics of the Remington Copper Solid sabot shotgun slug with standardized ballistic tests and used this information to predict tissue wounding patterns. This unique ammunition, first distributed in 1993, is composed of a solid copper, hollow-point slug with longitudinal slots cut into the nose. The slug is fitted into a hard plastic sabot with 8 finger-like projections and loaded into a shotgun shell with two plastic wads separating it from the underlying gunpowder charge. The ammunition was fired through a 12-gage shotgun using a rifled barrel, a smooth-bore barrel with rifled choke, and a smooth-bore barrel with a smooth modified choke into targets consisting of poster board and 10% ballistic gelatin at a variety of distances. The copper slug and plastic sabot created single 8-fingered asterisk-shaped defects in the poster board when fired at distances of less than 7 to 9 ft (approximately 2 to 3 m). All three barrel types performed similarly. At greater distances, the sabot impacted the targets separately from the slugs and created variably shaped defects that reflected base-first, nose-first, and side-first impacts. Increasing muzzle-to-target distances generally increased the impact distances between the slug and sabot. There was no predictable relationship between the sabot and slug impact points for any of the three barrel types. With each barrel tested, the wads created separate defects from the slug at distances greater than 5 ft (1.5 m). The distances between the slug and the wad impact points increased with increasing muzzle-to-target distances up to 40 ft (12 m), after which the wads generally no longer struck the targets. The slug created atypical defects at distances between 7 and 150 ft (approximately 2 to 45 m), probably due to yawing or tumbling. When the slug impacted the gelatin block in a nose-first orientation, the slotted nose portion tended to fragment and radially deposit pieces in the gelatin that were visible on radiographs. When the slug struck the gelatin target in a side-first orientation, it passed through the gelatin intact. The slug, sabot, and wads of this unique projectile separate and create independent impact points in a stereotypical manner independent of barrel type. This pattern of separation allows estimates to be made of ranges of fire. Wounds created in human tissues by this ammunition would likely have similar asterisk-shaped configurations, and nose fragments may be deposited in tissues and seen radiographically. Rectangular wounds created by the tumbling or yawing slug might be mistaken for intermediate target wounds.     

An empirical study on the close-range post-ricochet orientation of AK bullets (7.62 mm × 39 mm)

Most of the injuries and deaths from ricocheting bullets in shooting incidents are usually reported due to misaimed shots that had ricocheted close to the victims. Although the destabilisation of ricocheted bullets during their ricochet flights is a generally known phenomenon, no significant quantitative-based scientific studies have attempted to understand bullets’ post-ricochet orientations at close distances. This empirical study explores close-range post-ricochet orientations of AK bullets (7.62 mm × 39 mm) on a range of domestic surface types typically encountered during bullet ricochet incidents. This study has revealed that ricocheting AK bullets off of various wood types and tile samples produce side-on impacts into closely located targets following a rightwards yaw action. It has also been shown that AK bullets ricocheting off concrete and cement samples at 5-degree incident angles produced nose-forward impacts on paper witness screens, similar to an orthogonal impact of a direct-fired shot. The findings present important new information on the post-ricochet yawing behaviour of AK bullets, which has the potential to aid future shooting reconstructions in which victims are hit by closely ricocheted bullets.     

Prediction of Projectile Ricochet Behavior After Water Impact*

Abstract: Although not very common, forensic investigation related to projectile ricochet on water can be required when undesirable collateral damage occurs. Predicting the ricochet behavior of a projectile is challenging owing to numerous parameters involved: impact velocity, incident angle, projectile stability, angular velocity, etc. Ricochet characteristics of different projectiles (K50 BMG, 0.5‐cal Ball M2, 0.5‐cal AP‐T C44, 7.62‐mm Ball C21, and 5.56‐mm Ball C77) were studied in a pool. The results are presented to assess projectile velocity after ricochet, ricochet angle, and projectile azimuth angle based on impact velocity or incident angle for each projectile type. The azimuth ranges show the highest variability at low postricochet velocity. The critical ricochet angles were ranging from 15 to 30°. The average ricochet angles for all projectiles were pretty close for all projectiles at 2.5 and 10° incident angles for the range of velocities studied.     

Comparison of three DNA extraction methods for three different types of fired and unfired ammunition

When handling ammunition for gun loading, epithelial cells from the hands can become adhered to the metal surface, and this trace is a potential source of DNA. This work aimed to compare the efficiency of three DNA extraction methods from fired cartridge cases from three different types of firearms: a 12-gauge shotgun, a point 40 S&W pistol, and a 7.62 mm rifle. Nine volunteers were involved in this study handling 42 pieces of ammunition overall. The unfired ammunition was handled by a known good donor, and we used this data for comparison. DNA profiling was carried out with EZ1 DNA Investigator Kit for EZ1 Advanced XL automated DNA extraction, QIAmp DNA Investigator kit for a non-automated silica-based membrane column method, and direct lysis protocol for a non-automated in-house one. Samples were collected with 0.5 × 0.5 cm pieces of FTA filter paper moistened with distilled water. Quantiplex Pro RGQ kit and Fusion Powerplex 6C were used for genotyping samples. QIAmp DNA Investigator method resulted in the best number of alleles recovered for both conditions tested, both unfired and fired ammunitions: 77 % vs. 19.3 %, followed by the automated extraction (28.6 % vs. 4.3 %) and lysis protocol (0 % vs. 3.9 %). Degradation data from fired cartridge cases were 27 % for column method, 50 % for lysis protocol, and 87 % for EZ1 kit. Kruskal-Wallis test for mean DNA concentration from these samples returned p < 0.05, and Dunn’s multiple comparison test indicated a significant difference between calibers 0.40 S&W and 12-gauge shotgun from lyses protocol method. We did not detect any other significant differences on the test. The 12-gauge shotgun cartridge cases resulted in a high number of alleles overall (56.8 %). The numerous steps for DNA extraction and purification in the column method may explain its better performance. Although the results obtained indicate that all methods be used for DNA extraction from this type of evidence, the silica-based membrane column method appears to be more efficient.     

Bones, blood, pellets, glass, and no body.

A man was found guilty of killing his wife, although her body was never found. The case centered on her car, which contained fragments of bone, glass, shotgun pellets, and dried blood. Deoxyribonucleic acid (DNA) fingerprinting techniques were used to establish the decedent's identity. Examination of the bone fragments revealed that they were from the skull. These two pieces of information, added to other evidence, proved that the defendant's wife had received a fatal injury in her car, and a guilty verdict was rendered.