"The key fundamental principle in ballistics is the transfer of kinetic energy, derived from the equation Ek = 0.5mv2, where m is the projectile's mass and v is its velocity."
"The key fundamental principle in ballistics is the transfer of kinetic energy, derived from the equation Ek = 0.5mv2, where m is the projectile's mass and v is its velocity."
"a temporary cavity is formed by hydrostatic forces stretching the tissues surrounding the permanent cavity and radiate outwards, perpendicular to the projectile path."
"highly elastic tissues are the least susceptible to temporary cavitation and include lung and skeletal muscle."
"Some radiologists and trauma physicians advocate the use of markers placed on the skin at the site of the wounds to aid the radiologist reading the CT. These can be useful provided they do not create artefact that can be misinterpreted as foreign body material. Occasionally gunshot residue may be evident as high density material on the skin at an entry site."
"The key fundamental principle in ballistics is the transfer of kinetic energy, derived from the equation Ek = 0.5mv2, where m is the projectile's mass and v is its velocity."
"The calibre description of a firearm historically refers to the internal diameter of the barrel before the grooves were machined into the barrel, which are typically measured in fractions of an inch in the U.S. and millimetres in Europe. An example is the common 22 calibre representing a barrel diameter of 0.22 inches. However, in reality gun manufacturers use calibre to variably refer to the barrel diameter with or without grooves or the diameter of the bullet."
"Shotgun barrel diameter is described by gauge (or bore) rather than calibre and is historically based on the fraction of a pound of a solid lead sphere that would fit into the bore. An example is a 12G shotgun where the barrel will allow a lead ball weighing 1/12th of a pound."
"The fundamental unit of firearm ammunition is the cartridge or round. It contains a projectile (or projectiles), a propellant and an ignition primer all held together by a case. Projectile velocities vary substantially depending on ammunition and firearm type, and in general velocity is referred to as low if below the speed of sound (340 m/s) 1-4."
"The fundamental unit of firearm ammunition is the cartridge or round. It contains a projectile (or projectiles), a propellant and an ignition primer all held together by a case. Projectile velocities vary substantially depending on ammunition and firearm type, and in general velocity is referred to as low if below the speed of sound (340 m/s) 1-4."
"Terminal ballistics describes the effects of projectiles on a target. Wound ballistics is a subset of terminal ballistics, referring to the effects of projectiles on living tissues and is of importance to the trauma radiologist assessing medical imaging of patients with projectile injuries. Traumatic injuries are the result of the transfer of kinetic energy from projectiles to human tissue. Injury type and severity are affected by projectile and tissue factors:"
"perforating injuries: referring to injuries where the projectile enter and exit the body with minor tissue loss"
"a permanent cavity is formed along the path of the projectile, following the initial laceration and crush injury"
"a temporary cavity is formed by hydrostatic forces stretching the tissues surrounding the permanent cavity and radiate outwards, perpendicular to the projectile path."
"The key fundamental principle in ballistics is the transfer of kinetic energy, derived from the equation Ek = 0.5mv2, where m is the projectile's mass and v is its velocity."
"External ballistics is the science of projectiles in flight, that is the time between discharge of the firearm to entry into the target. Drag produced by air (air resistance) significantly affects the flight of the projectile and is primarily dependent on the projectile surface area. Projectile characteristics that reduce surface area will lead to less air resistance and more stable flight trajectory. Effective surface area increases if the projectile long axis deviates from the direction of flight thereby creating trajectory instability. This is termed yaw, which is slow and akin to a sweeping motion. Yaw is analogous to proton precession in a magnetic field B0. Yaw is centred on the projectile centre of mass and when extreme enough, the projectile can tumble during flight which greatly increases effective surface area and leads to a suboptimal trajectory profile. Nutation, smaller changes in the axis of rotation akin to nodding also contributes to trajectory instability. By reducing the distance of the muzzle to the target, drag is reduced allowing greater kinetic energy deposition into the target."
"a permanent cavity is formed along the path of the projectile, following the initial laceration and crush injury"
"a temporary cavity is formed by hydrostatic forces stretching the tissues surrounding the permanent cavity and radiate outwards, perpendicular to the projectile path."
"The calibre description of a firearm historically refers to the internal diameter of the barrel before the grooves were machined into the barrel, which are typically measured in fractions of an inch in the U.S. and millimetres in Europe. An example is the common 22 calibre representing a barrel diameter of 0.22 inches. However, in reality gun manufacturers use calibre to variably refer to the barrel diameter with or without grooves or the diameter of the bullet."
"Higher velocity projectiles and those with greater yaw increase the size of the temporary cavity"
"Significant energy is imparted to bone by projectiles leading to fracture as bones is very dense. In projectile injuries with minimal or no yaw, a characteristic fracture appearance occurs in flat bones (e.g. skull, sternum and ribs) with a bevelled edge. Bevelling occurs due to the forward movement of force, creating a cone-shaped deformity as the projectile pushes through the layers of bone. The projectile initially fractures the first cortex (this could be the inner or outer table of the skull) creating a small entry margin of the bevel (internal bevel). Then travelling along its path, the second cortex is fractured with a wider exit margin (external bevel). The internal bevel may be accentuated in areas of very high dense bone such as the petrous temporal bone. Beyond the bone, osseous fragments and debris can get pulled along the track of the continuing projectile, which therefore can help determine directionality. With high velocity projectiles exerting massive supersonic forces, an explosive pattern of injury may be seen, especially in the skull."
"This is uncommon and more likely with shot rather than a single bullet. It occurs most often in the arterial system but has been reported in the portal system and the intracranial and pulmonary circulations. The heart and aorta are the most common site of entry. Embolisation typically occurs at the time of injury but delayed embolisation (up to 4 weeks later) has been observed. Not unsurprisingly, venous emboli are typically found in the right heart chambers or pulmonary arteries and arterial emboli in the extremities. The key to radiological diagnosis is retained projectiles remote to the entry wound or trajectory or changing position of the projectiles over serial imaging. Projectiles can also migrate when initially coming to rest in other body regions, such as bullets found in the GIT or lungs from entry via the mouth or neck."
"Plumbism refers to systemic lead toxicity and it is extremely rare after projectile injury. Due to the number of shot pellets, it is more commonly seen in patients with retained shot rather than single bullets. Most cases arise from the retained projectile being lodged within a joint, a bone or an intervertebral disk. Intra-articular retention leading to plumbism is classically described in the literature due to the synovial fluid being capable of dissolving lead."
Expected headings
"Internal ballistics"
"Types of firearms"
"Handguns"
"Rifles"
"Shotguns"
"Submachine guns"
"Machine guns"
"Other firearm types"
"Rifling"
"Firearm size"
"Types of ammunition"
"Cartridge case"
"Primer"
"Propellant"
"Projectiles"
"Firearm discharge"
"External ballistics"
"Terminal ballistics"
"Projectile interactions within tissues"
"Types of wounds"
"Mechanisms of tissue injury"
"Laceration and crushing"
"Cavitation"
"Shock waves"
"Entry and exit wounds"
"Bone bevelling"
"Keyhole defect"
"Other biological manifestations of ballistic injury"
"Bullet embolisation"
"Secondary infection"
"Plumbism"
"There are five basic types of firearms."
"There are three main types of projectiles 1,2 :"
"include single shot pistols, derringers, revolvers and automatic pistols"
"ammunition also include wadding (or piston) between the propellant and the projectiles which is made of plastic, paper or fibre and maximises transmitted energy to the shot"
"include single shot, over and under, double barrel, bolt action, pump action and autoloading varieties"
"the bullet, jacket and gas check may be detached from each other and enter the target separately"
"projectile mass, composition and construction, entry velocity and trajectory"
"tissue type (viscoelastic tissue characteristics which include elasticity, density and internal cohesiveness) and presence of pre-existing disease"
"the most susceptible tissues to temporary cavitation are those with low elasticity due to water-like tissue density such as brain, liver and spleen and fluid-filled organs including the heart, bladder, bowel and vessels"
"the most susceptible tissues to temporary cavitation are those with low elasticity due to water-like tissue density such as brain, liver and spleen and fluid-filled organs including the heart, bladder, bowel and vessels"
"fires an intermediate rifle cartridge (e.g. 5.56 x 45 mm or 7.62 x 39 mm)"
"a carbine generally refers to a rifle (or any long gun) with a relatively shortened barrel, making them easier to handle for troops working in confined spaces (e.g. vehicle mounted)"
"Significant energy is imparted to bone by projectiles leading to fracture as bones is very dense. In projectile injuries with minimal or no yaw, a characteristic fracture appearance occurs in flat bones (e.g. skull, sternum and ribs) with a bevelled edge. Bevelling occurs due to the forward movement of force, creating a cone-shaped deformity as the projectile pushes through the layers of bone. The projectile initially fractures the first cortex (this could be the inner or outer table of the skull) creating a small entry margin of the bevel (internal bevel). Then travelling along its path, the second cortex is fractured with a wider exit margin (external bevel). The internal bevel may be accentuated in areas of very high dense bone such as the petrous temporal bone. Beyond the bone, osseous fragments and debris can get pulled along the track of the continuing projectile, which therefore can help determine directionality. With high velocity projectiles exerting massive supersonic forces, an explosive pattern of injury may be seen, especially in the skull."