อยากขอความกรุณาพี่ๆ เพื่อนๆที่มีความรู้ความสามารถทางภาษาอังกฤษ
ช่วยแปลบทความด้านล่างนี้ให้ทีนะคะ แปลแบบคร่าวๆก็ยังดีค่ะ
ต้องใช้สอบวันพรุ่งนี้ แต่อ่านแล้วไม่เข้าใจจริงๆค่ะ
The range of the handgun ammunition with the non-lead projectiles made by the compression of a metal powder or a mixture of metal powders has been growing since the beginning of the 21st century. This specific type of ammunition, called as frangible ammunition, is designed to disintegrate on impact and are intended mainly for use during training by law enforcement agencies because of their relative safety (low ricochet hazard) and low toxicity.1,2 However, new types of frangible ammunition that have been developed for combat situations and self-defense have also recently appeared on the market. Most frangible ammunition has been designed for handguns, but recently frangible ammunition for rifles has also been developed.
Both medical and forensic experts must be made aware of the new injury patterns resulting from the use of frangible projectiles.
Frangible ammunition is unique because of its terminal ballistic properties.3,4 The projectiles show only limited penetration capability and have a reduced ricochet hazard because they fragment after impact with a hard target.1,2,5 The ballistic properties of frangible projectiles depend on their specific manu facturing processes. Frangible projectiles are mainly manufactured by powder metallurgy (usually cold molding) of composite materials based on fine metal powders (including copper, iron, zinc, tin, bismuth, and tungsten; Fig. 1). Frangible projectiles are considered to be relatively ecologically sensitive because they have no lead content.1,2
For the non-professional, it is often very difficult to visually distinguish frangible projectiles from full metal jacketed projectiles with a lead core (Fig. 2), which could lead to mistakes. Some frangible projectiles can be recognized by their characteristic shape and color, and frangible projectiles usually have a flat point nose.1e3 The nature of projectiles can only be reliably determined by special testing (such as hardness testing, fragility and strength testing, or microscopic inspection).
Even when the projectiles do not leave the body, only small fragments can be found in the wounded tissues.2e4 Frangible projectiles present a wide range of new technical challenges to the field of ballistics analysis.2 From a criminological point of view, the most important disadvantage of frangible ammunition is the very limited ability to identify ballistic traces on the surfaces of fragmented projectiles.1,2,4
The aim of this article is to draw attention to the existence of frangible and ultra-frangible ammunition. The first part of this article describes the design and function of frangible projectiles. The second part reports the results of gunshot wounds caused by ultra-frangible projectiles in blocks of ballistic gel and the hind leg of a pig.
2. Design and properties of frangible ammunition
Frangible projectiles are generally designed to disintegrate after impact with a hard target. The resulting fragments are significantly smaller than the original projectile.
A classical compact frangible projectile usually fragments after impact with a rigid, hard target. The size of the created fragments is closely related to the rigidity of the target (Fig. 3). Standard frangible projectiles do not usually disintegrate after impact with a lowrigidity target (such as a thin metal sheet, wooden plate, glass window, or porous building materials). In cases of impact with a high resistance hard target (such as a thick metal sheet, armor plate, concrete or brick wall, or automobile windscreen), frangible projectiles disintegrate into a large number of small fragments which do not usually penetrate the target.1e3 The fragmentation pattern is influenced by the impact velocity and impact angle of the projectile. The size of the fragments usually decreases as the impact velocity increases.
The most common frangible projectiles do not fragment or deform after penetration of soft tissues.4 In this regard, their behavior in soft tissues is very similar to the behavior of standard full metal jacketed projectiles. Frangible projectiles may fragment after impact with bone, in the same way as after impact with other hard targets.4 However, some frangible projectiles with a suitably shaped cavity in the front part disintegrate into a large number of fragments after penetration of soft tissues, even if they do not make contact with bone. These are known as ultra-frangible projectiles. The first ultra-frangible projectiles have recently been developed, tested, and used. Examples of ultra-frangible projectiles include the American commercially manufactured Extreme Shock Fang Face (FF) and Air Freedom Round (AFR) and the experimental frangible SRK-2 projectiles, manufactured in the Czech Republic (Fig. 4). The FF and AFR projectiles (Fig. 5) are intended for use by both law enforcement agencies and the general public (for training, selfdefense, and hunting). The Varmint Grenade rifle ammunition, consisting of a brass jacket filled with a lightly compressed mixture of copper and tin powders, which is produced by the Barnes Company, has similar design and performance features (Fig. 6).2
Ultra-frangible projectiles typically disintegrate into fragments when shot into blocks of soft tissue substitute (such as ballistic gel) or animal body parts. This feature was extensively tested during their development.1,5,6 It is therefore probable that they will also disintegrate when shot into human soft tissues. Ultrafrangible projectiles shot by handguns and especially rifles create temporary large-volume cavities in blocks of ballistic gel, which often completely destroys the block. The wounding effects of these projectiles are comparable with those of explosive
projectiles.
3. Wounding effects of frangible and ultra-frangible projectiles
Properly designed frangible projectiles have the correct ratio of strength and toughness to deformation capability and brittleness.1,2 Frangible projectiles must be compact and strong enough to withstand the load during the shot, the free flight to the target, and tissue penetration, and must also be brittle enough to reliably fragment after impact with a defined hard target.
The compactness of the brittle material in the frangible projectile has a significant effect on the wounding effects during both soft tissue penetration and impact with bone.6,7 The projectiles cause significant wounding effects during disintegration in soft tissues owing to tissue damage caused by the large-volume of the temporary cavity.
Unlike compact projectiles, ultra-frangible projectiles do not create a classical wound channel during tissue penetration. Instead, the fragments create dozens of smaller wound channels.4,6,7 The large numbers of irregularly shaped fragments cause a largevolume cone-shaped wound, which damages muscle fibers, nerves, and vessels. The penetrating capability of these particles is limited, and depends on their size and mass. A pistol projectile may reach a depth of up to 15 cm. Ultra-frangible projectiles do not exit the body, and therefore present no risk to bystanders. The risks of causing serious wounds to bystanders through the ricocheting of small fragments and powder after impact with a hard target are minimal.
To analyze the wounding potential of ultra-frangible projectiles, we performed a shooting experiment. We fired projectiles from a ballistic measuring device into blocks of ballistic gel and the hind leg of a pig. The distance between the muzzle of the barrel and the target was 5 m, and the projectile’s velocity at the distance 2.5 m from the muzzle of the ballistic measuring device was measured. We used SRK-2 experimental cartridges (Fig. 4) containing iron powder. The mass of the projectile with the frontal conical cavity was 4.8 g (74 grain bullet, caliber 9 mm
Luger).
4. Conclusion
Information about the wounding effects of these types of ammunition is very sparse to date. In our shooting experiments, we found that the terminal behavior of selected ultra-frangible projectiles was similar in a block of ballistic gel and the soft tissues of the hind leg of a pig, except that the degree of disintegration was less in the block of ballistic gel. As a large variety of frangible ammunition is being designed and its commercial availability will probably expand in the near future, it is likely that injuries resulting from the use of this ammunition will become more common, ranging from uncomplicated limb injuries to fatal internal organ injuries. The increased worldwide use of ultra-frangible projectiles with high wounding effects will require further research of associated technical, forensic ballistic, medical, and legal issues.
ขอความกรุณาช่วยแปลภาษาอังกฤษด่วนค่ะ
ช่วยแปลบทความด้านล่างนี้ให้ทีนะคะ แปลแบบคร่าวๆก็ยังดีค่ะ
ต้องใช้สอบวันพรุ่งนี้ แต่อ่านแล้วไม่เข้าใจจริงๆค่ะ
The range of the handgun ammunition with the non-lead projectiles made by the compression of a metal powder or a mixture of metal powders has been growing since the beginning of the 21st century. This specific type of ammunition, called as frangible ammunition, is designed to disintegrate on impact and are intended mainly for use during training by law enforcement agencies because of their relative safety (low ricochet hazard) and low toxicity.1,2 However, new types of frangible ammunition that have been developed for combat situations and self-defense have also recently appeared on the market. Most frangible ammunition has been designed for handguns, but recently frangible ammunition for rifles has also been developed.
Both medical and forensic experts must be made aware of the new injury patterns resulting from the use of frangible projectiles.
Frangible ammunition is unique because of its terminal ballistic properties.3,4 The projectiles show only limited penetration capability and have a reduced ricochet hazard because they fragment after impact with a hard target.1,2,5 The ballistic properties of frangible projectiles depend on their specific manu facturing processes. Frangible projectiles are mainly manufactured by powder metallurgy (usually cold molding) of composite materials based on fine metal powders (including copper, iron, zinc, tin, bismuth, and tungsten; Fig. 1). Frangible projectiles are considered to be relatively ecologically sensitive because they have no lead content.1,2
For the non-professional, it is often very difficult to visually distinguish frangible projectiles from full metal jacketed projectiles with a lead core (Fig. 2), which could lead to mistakes. Some frangible projectiles can be recognized by their characteristic shape and color, and frangible projectiles usually have a flat point nose.1e3 The nature of projectiles can only be reliably determined by special testing (such as hardness testing, fragility and strength testing, or microscopic inspection).
Even when the projectiles do not leave the body, only small fragments can be found in the wounded tissues.2e4 Frangible projectiles present a wide range of new technical challenges to the field of ballistics analysis.2 From a criminological point of view, the most important disadvantage of frangible ammunition is the very limited ability to identify ballistic traces on the surfaces of fragmented projectiles.1,2,4
The aim of this article is to draw attention to the existence of frangible and ultra-frangible ammunition. The first part of this article describes the design and function of frangible projectiles. The second part reports the results of gunshot wounds caused by ultra-frangible projectiles in blocks of ballistic gel and the hind leg of a pig.
2. Design and properties of frangible ammunition
Frangible projectiles are generally designed to disintegrate after impact with a hard target. The resulting fragments are significantly smaller than the original projectile.
A classical compact frangible projectile usually fragments after impact with a rigid, hard target. The size of the created fragments is closely related to the rigidity of the target (Fig. 3). Standard frangible projectiles do not usually disintegrate after impact with a lowrigidity target (such as a thin metal sheet, wooden plate, glass window, or porous building materials). In cases of impact with a high resistance hard target (such as a thick metal sheet, armor plate, concrete or brick wall, or automobile windscreen), frangible projectiles disintegrate into a large number of small fragments which do not usually penetrate the target.1e3 The fragmentation pattern is influenced by the impact velocity and impact angle of the projectile. The size of the fragments usually decreases as the impact velocity increases.
The most common frangible projectiles do not fragment or deform after penetration of soft tissues.4 In this regard, their behavior in soft tissues is very similar to the behavior of standard full metal jacketed projectiles. Frangible projectiles may fragment after impact with bone, in the same way as after impact with other hard targets.4 However, some frangible projectiles with a suitably shaped cavity in the front part disintegrate into a large number of fragments after penetration of soft tissues, even if they do not make contact with bone. These are known as ultra-frangible projectiles. The first ultra-frangible projectiles have recently been developed, tested, and used. Examples of ultra-frangible projectiles include the American commercially manufactured Extreme Shock Fang Face (FF) and Air Freedom Round (AFR) and the experimental frangible SRK-2 projectiles, manufactured in the Czech Republic (Fig. 4). The FF and AFR projectiles (Fig. 5) are intended for use by both law enforcement agencies and the general public (for training, selfdefense, and hunting). The Varmint Grenade rifle ammunition, consisting of a brass jacket filled with a lightly compressed mixture of copper and tin powders, which is produced by the Barnes Company, has similar design and performance features (Fig. 6).2
Ultra-frangible projectiles typically disintegrate into fragments when shot into blocks of soft tissue substitute (such as ballistic gel) or animal body parts. This feature was extensively tested during their development.1,5,6 It is therefore probable that they will also disintegrate when shot into human soft tissues. Ultrafrangible projectiles shot by handguns and especially rifles create temporary large-volume cavities in blocks of ballistic gel, which often completely destroys the block. The wounding effects of these projectiles are comparable with those of explosive
projectiles.
3. Wounding effects of frangible and ultra-frangible projectiles
Properly designed frangible projectiles have the correct ratio of strength and toughness to deformation capability and brittleness.1,2 Frangible projectiles must be compact and strong enough to withstand the load during the shot, the free flight to the target, and tissue penetration, and must also be brittle enough to reliably fragment after impact with a defined hard target.
The compactness of the brittle material in the frangible projectile has a significant effect on the wounding effects during both soft tissue penetration and impact with bone.6,7 The projectiles cause significant wounding effects during disintegration in soft tissues owing to tissue damage caused by the large-volume of the temporary cavity.
Unlike compact projectiles, ultra-frangible projectiles do not create a classical wound channel during tissue penetration. Instead, the fragments create dozens of smaller wound channels.4,6,7 The large numbers of irregularly shaped fragments cause a largevolume cone-shaped wound, which damages muscle fibers, nerves, and vessels. The penetrating capability of these particles is limited, and depends on their size and mass. A pistol projectile may reach a depth of up to 15 cm. Ultra-frangible projectiles do not exit the body, and therefore present no risk to bystanders. The risks of causing serious wounds to bystanders through the ricocheting of small fragments and powder after impact with a hard target are minimal.
To analyze the wounding potential of ultra-frangible projectiles, we performed a shooting experiment. We fired projectiles from a ballistic measuring device into blocks of ballistic gel and the hind leg of a pig. The distance between the muzzle of the barrel and the target was 5 m, and the projectile’s velocity at the distance 2.5 m from the muzzle of the ballistic measuring device was measured. We used SRK-2 experimental cartridges (Fig. 4) containing iron powder. The mass of the projectile with the frontal conical cavity was 4.8 g (74 grain bullet, caliber 9 mm
Luger).
4. Conclusion
Information about the wounding effects of these types of ammunition is very sparse to date. In our shooting experiments, we found that the terminal behavior of selected ultra-frangible projectiles was similar in a block of ballistic gel and the soft tissues of the hind leg of a pig, except that the degree of disintegration was less in the block of ballistic gel. As a large variety of frangible ammunition is being designed and its commercial availability will probably expand in the near future, it is likely that injuries resulting from the use of this ammunition will become more common, ranging from uncomplicated limb injuries to fatal internal organ injuries. The increased worldwide use of ultra-frangible projectiles with high wounding effects will require further research of associated technical, forensic ballistic, medical, and legal issues.