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Ballistic gelatin is a testing medium designed to simulate the effects of bullet wounds in animal muscle tissue. It was developed and improved by Martin Fackler and others in the field of wound ballistics. It is calibrated to match pig muscle, which is ballistically similar to human muscle tissue. [1] [2] [3]
Ballistic gelatin is traditionally a solution of gelatin powder in water. Ballistic gelatin closely simulates the density and viscosity of human and animal muscle tissue, and is used as a standardized medium for testing the terminal performance of firearms ammunition. While ballistic gelatin does not model the tensile strength of muscles or the structures of the body such as skin and bones, it works fairly well as an approximation of tissue and provides similar performance for most ballistics testing; however, its usefulness as a model for very low velocity projectiles can be limited. Ballistic gelatin is used rather than actual muscle tissue due to the ability to carefully control the properties of the gelatin, which allows consistent and reliable comparison of terminal ballistics.
The FBI introduced its own testing protocol in December 1988 as a response to the 1986 Miami shootout, and it quickly became popular among US law enforcement agencies.
The most commonly used formula is an FBI-style 10% ballistic gelatin, which is prepared by dissolving one part 250 bloom type A gelatin into nine parts of warm water (by mass), mixing the water while pouring in the powdered gelatin. It is chilled to 4 °C (39 °F).[ citation needed ] The older NATO formula specifies a 20% solution, chilled to 10 °C (50 °F), but that solution costs more to prepare, as it uses twice the amount of the gelatin.
In either case, a 1988 research paper by Martin Fackler recommends that the water should not be heated above 40 °C (104 °F), as this can cause a significant change in the ballistic performance. [4] However, this result does not seem to be reproduced in a later study. [5]
To ensure accurate results, immediately prior to use, the gelatin block is calibrated by firing a standard .177 caliber (4.5 mm) steel BB from an air gun over a gun chronograph into the gelatin, and the depth of penetration measured. While the exact calibration methods vary slightly, the calibration method used by the United States Immigration and Naturalization Service's National Firearms Unit is fairly typical. It requires a velocity of 183 ± 3 m/s (600 ± 10 ft/s), and a BB penetration between 8.3 and 9.5 cm (3.3–3.7 in). [6]
In his book Bullet Penetration, ballistics expert Duncan MacPherson describes a method that can be used to compensate for ballistic gelatin that gives a BB penetration that is off by several centimeters (up to two inches) in either direction. MacPherson's Figure 5-2, Velocity Variation Correction to Measured BB Penetration Depth, can be used to make corrections to BB penetration depth when measured BB velocity is within ±10 m/s of 180 m/s. This method can also be used to compensate for error within the allowed tolerance, and normalize results of different tests, as it is standard practice to record the exact depth of the calibration BB's penetration. [7]
Ballistic gels made from natural gelatin are typically clear yellow-brown in color, and are generally not re-usable. The more expensive synthetic substitutes are engineered to simulate the ballistic properties of natural gelatin, whilst initially being colorless and clear. Some synthetic gels are also re-usable, since they can be melted and reformed without affecting the ballistic properties of the gels.[ citation needed ]
Synthetic ballistic gels are typically made of an oil and a polymer instead of gelatin and water, most commonly used is white mineral oil and a styrene polymer blend, polymers used include:
The gel usually includes about 12% to 22% by weight of the polymer, but it depends on what polymers is used.
Heating temperatures vary depending on what polymer and oil is used, but should never go over 275 °F (135 °C).
The polymer and oil solution is extremely sensitive to moisture - when moisture comes in contact with the solution, bubbles form when heat is applied.
Polymer should not be added to heated up oil like gelatin is to water; the polymer and oil should be mixed when no heat is present.
Dwell times are recommended after mixing the polymer and oil to prevent bubbles forming when heat is applied. These "dwell" times can go up to 12 hours if the air is above about 60 °F, or at the very least 24 hours if the air is at cooler temperatures.
These discoveries were made by Darryl D. Amick. [8]
Since ballistic gelatin mimics the properties of muscle tissue reasonably well, [9] it is the preferred medium (over real porcine cadavers) for comparing the terminal performance of different expanding ammunition, such as hollow-point and soft-point bullets. These bullets use the hydraulic pressure of the tissue or gelatin to expand in diameter, limiting penetration and increasing the tissue damage along their path. While the Hague Convention restricts the use of such ammunition in warfare, it is commonly used by police and civilians in defensive weapons, as well as police sniper and hostage-rescue teams, where rapid disabling of the target and minimal risk of overpenetration are required to reduce collateral damage.
Bullets intended for hunting are also commonly tested in ballistic gelatin. A bullet intended for use hunting small vermin, such as prairie dogs, for example, needs to expand very quickly to have an effect before it exits the target, and must perform at higher velocities due to the use of lighter bullets in the cartridges. The same fast-expanding bullet used for prairie dogs would be considered inhumane for use on medium game animals like whitetail deer, where deeper penetration is needed to reach vital organs and assure a quick kill.
In television the MythBusters team sometimes used ballistics gel to aid in busting myths, but not necessarily involving bullets, including the exploding implants myth, the deadly card throw, and the ceiling fan decapitation. They sometimes placed real bones (from humans or pigs) or synthetic bones in the gel to simulate bone breaks as well.
The US television program Forged in Fire is also known to use ballistics gelatin, often creating entire human torsos and heads complete with simulated bones, blood, organs and intestines that are cast inside the gel. Various bladed weapons are then tested on the gel torso in order to simulate and record the destructive effects the weapons would have on a real human body.
Hydrostatic shock, also known as Hydro-shock, is the controversial concept that a penetrating projectile can produce a pressure wave that causes "remote neural damage", "subtle damage in neural tissues" and "rapid effects" in living targets. It has also been suggested that pressure wave effects can cause indirect bone fractures at a distance from the projectile path, although it was later demonstrated that indirect bone fractures are caused by temporary cavity effects.
A bullet is a kinetic projectile, a component of firearm ammunition that is shot from a gun barrel. They are made of a variety of materials, such as copper, lead, steel, polymer, rubber and even wax; and are made in various shapes and constructions, including specialized functions such as hunting, target shooting, training, and combat. Bullets are often tapered, making them more aerodynamic. Bullet size is expressed by weight and diameter in both imperial and metric measurement systems. Bullets do not normally contain explosives but strike or damage the intended target by transferring kinetic energy upon impact and penetration.
A hollow-point bullet is a type of expanding bullet which expands on impact with a soft target, transferring more or all of the projectile's energy into the target over a shorter distance.
Terminal ballistics is a sub-field of ballistics concerned with the behavior and effects of a projectile when it hits and transfers its energy to a target.
Ballistics is the field of mechanics concerned with the launching, flight behaviour and impact effects of projectiles, especially ranged weapon munitions such as bullets, unguided bombs, rockets or the like; the science or art of designing and accelerating projectiles so as to achieve a desired performance.
The .380 ACP, is a rimless, straight-walled pistol cartridge that was developed by firearms designer John Moses Browning. The cartridge headspaces on the mouth of the case. It was introduced in 1908 by Colt, for use in its new Colt Model 1903 Pocket Hammerless semi-automatic, and has been a popular self-defense cartridge ever since, seeing wide use in numerous handguns. Other names for .380 ACP include 9mm Browning, 9mm Corto, 9mm Kurz, 9mm Short, and 9mm Browning Court. It should not be confused with .38 ACP. The .380 ACP does not strictly conform to cartridge naming conventions, named after the diameter of the bullet, as the actual bullet diameter of the .380 ACP is .355 inches.
The .357 SIG is a bottlenecked rimless centrefire handgun cartridge developed by the Swiss-German firearms manufacturer SIG Sauer, in cooperation with ammunition manufacturer Federal Premium. The cartridge is used by a number of law enforcement agencies.
The .357 Smith & Wesson Magnum, .357 S&W Magnum, .357 Magnum, or 9×33mmR is a smokeless powder cartridge with a 0.357 in (9.07 mm) bullet diameter. It was created by Elmer Keith, Phillip B. Sharpe, and Douglas B. Wesson of firearm manufacturers Smith & Wesson and Winchester. The .357 Magnum cartridge is notable for its highly effective terminal ballistics.
The 9×19mm Parabellum is a rimless, centerfire, tapered firearms cartridge.
Nosler, Inc. is an American manufacturing company based in Bend, Oregon, known for producing ammunition and handloading components and specializing in high-performance hollow-point and soft-point hunting bullets. The current companies also include subsidiaries Nosler Custom and Nosler Reloading. Nosler's contributions to shooting sports include both polymer-tipped bullet designs and new manufacturing techniques used in their production.
Stopping power is the ability of a weapon – typically a ranged weapon such as a firearm – to cause a target to be incapacitated or immobilized. Stopping power contrasts with lethality in that it pertains only to a weapon's ability to make the target cease action, regardless of whether or not death ultimately occurs. Which ammunition cartridges have the greatest stopping power is a much-debated topic.
Martin L. Fackler (1933–2015) was an American military officer, surgeon and wound ballistics expert. He served in the U.S Navy from 1960 to 1975 and in the U.S. Army from 1975 to 1991. He was a field surgeon at the Naval Support Hospitals at Da Nang, Vietnam and at Yokosuka, Japan, and later a colonel in the US Army's Medical Corps. He was the founder and head of the Wound Ballistics Laboratory for the Letterman Army Institute of Research from 1981 to 1991. He was a member and leader of numerous distinguished organizations, among them the International Wound Ballistics Association, the French Wound Ballistics Society and the American Academy of Forensic Sciences. Dr. Fackler had numerous teaching appointments and was the author of over 300 publications in regards to wound ballistics, body armor, and treatment of injuries for both the military and civilian populations. He is credited with a number of contributions to the field of terminal ballistics, including:
The 5.45×39mm cartridge is a rimless bottlenecked intermediate cartridge. It was introduced into service in 1974 by the Soviet Union for use with the new AK-74. The 5.45×39mm gradually supplemented and then largely replaced the 7.62×39mm cartridge in Soviet and Warsaw Pact service as the primary military service rifle cartridge.
Handgun effectiveness is a measure of the stopping power of a handgun: its ability to incapacitate a hostile target as quickly and efficiently as possible.
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Federal Premium Ammunition is a wholly-owned subsidiary of Vista Outdoor, located in Anoka, Minnesota. With a workforce of nearly 1,500, Federal manufactures shotshell, centerfire, and rimfire ammunition and components.
A comparison microscope is a device used to analyze side-by-side specimens. It consists of two microscopes connected by an optical bridge, which results in a split view window enabling two separate objects to be viewed simultaneously. This avoids the observer having to rely on memory when comparing two objects under a conventional microscope.
A gunshot wound (GSW) is a penetrating injury caused by a projectile from a gun. Damage may include bleeding, bone fractures, organ damage, wound infection, loss of the ability to move part of the body, and in severe cases, death. Damage depends on the part of the body hit, the path the bullet follows through the body, and the type and speed of the bullet. Long-term complications can include bowel obstruction, failure to thrive, neurogenic bladder and paralysis, recurrent cardiorespiratory distress and pneumothorax, hypoxic brain injury leading to early dementia, amputations, chronic pain and pain with light touch (hyperalgesia), deep venous thrombosis with pulmonary embolus, limb swelling and debility, and lead poisoning.
Penetrating trauma is an open wound injury that occurs when an object pierces the skin and enters a tissue of the body, creating a deep but relatively narrow entry wound. In contrast, a blunt or non-penetrating trauma may have some deep damage, but the overlying skin is not necessarily broken and the wound is still closed to the outside environment. The penetrating object may remain in the tissues, come back out the path it entered, or pass through the full thickness of the tissues and exit from another area.