Bullets can also be said to be the product of civilization integrating physics, chemistry, materials science, aerodynamics and technology. Although its use is related to killing people, bullets are still the only choice for human beings before the emergence of new technologies to project energy.
Basic introduction Chinese name: bullet mbth:Ball；; ; Bullets; Powder and bullets; Take a shot; Pinyin of slug: zǐ dàn alias: bullet/ammunition source: interpretation of Qinglongtan, basic interpretation, quotation interpretation, design principle, basic structure, lethality, basic classification, ordinary bomb, tracer bomb, incendiary bomb, armor-piercing incendiary bomb, instantaneous explosive bomb, short bomb, empty bomb, intelligent bomb, shell-less bomb, liquid bomb and multi-head bomb. Eavesdropping bombs, warhead improvement, shooting into the air, turning rumors, explaining the basic explanation of cylindrical bombs fired by rifles, muskets or pistols (such as lead, steel or lead-cored steel shells). 1, artillery ammunition, generally cylindrical at the back and conical at the front, is generally made of lead, steel or lead-core steel shell; 2. Chongqing or Sichuan dialect: usually refers to money. Quotes and explanations are bullets. It consists of shell, primer, propellant and warhead. When launching, the firing pin hits the primer, which makes the propellant burn and produces gas to push the warhead out. Hong Shen's "Green Dragon Pool" Act IV: "Many of you have guns and bullets in your hands! Many people are holding foreign guns for the first time! If it is not made public according to law, it will brew life! " Yang Shuo's Dust Collection: "Two carts full of arms, followed by a small team of trench soldiers, each carrying a bullet, so heavy that even the pole was slightly bent." Design principle No matter what style or shape of bullet, it is composed of four parts: projectile, shell, propellant and primer. For bullets, no matter what purpose they are used for, most propellants commonly used in the world are smokeless powder: smokeless powder can be divided into (single base, double base and triple base) (its main component is nitrocellulose), and firearms use single base powder. Different firearms have different requirements. For example, pistols mostly use porous fast-burning single-base drugs. Rifle is a single-hole granular single-base powder with polished and passivated surface. The primer of bullet dissection consists of fire hole, firing anvil and firing agent. Its function is to generate flame when igniting, and ignite the propellant quickly and safely. When firing, the firing agent is ignited by the impact of the firing pin and the firing anvil, and the flame ignites the propellant through the fire hole. When igniting, the needle will activate the ignition cap (primer). Primer quickly burns and ignites the propellant in the shell, and at the same time produces instantaneous combustion, high temperature and high pressure, which pushes the projectile (warhead) out of the shell. At this time, the projectile is pushed forward by the high pressure generated by the propellant, squeezed by the rifling, rotated and finally pushed out of the bore. The basic structure of a general bullet consists of four parts: projectile, shell, propellant and fire cap. The projectile penetrates the target through rapid flight, the shell casing is used to connect the projectile and protect the propellant and sealed gunpowder gas, while the propellant gives the projectile a high initial velocity through combustion, and the fire cap is used for firing. However, this only refers to ordinary bullets. Other special bullets, detection bullets and auxiliary bullets are different, and the composition will vary with different bullets. Copper clad steel shell 1- warhead shape: 1- warhead; 2- Propellant; 3- cartridge case; 4- Primer. Lethality Theoretically, the lethality of a bullet is determined by the interaction between operating force and bouncing force. Penetration The penetrating power of a bullet, also known as penetration or penetration, refers to the ability of a bullet to drill into or penetrate an object. Its size mainly depends on the mass of the warhead, the cross-sectional density of the warhead and the speed when it hits an object, and is usually expressed by the depth of penetration into an object. The penetration of modern rifle bullets is generally strong, such as NATO's 7.62x5 1(7.62 stands for bullet caliber, 5 1 stands for shell length, in millimeters), and bullets can penetrate a homogeneous steel plate with a thickness of 6 mm within 100 meters. Spring force refers to the effectiveness of making the target lose mobility after the warhead hits the target. The stronger the braking force, the less time it takes for the target to lose its mobility, and the weaker the braking force, the more time it takes for the target to lose its mobility. Because of the complex structure of human body, hitting different parts will produce different effects. Therefore, the stopping power is different from the penetrating power and cannot be measured by a unified standard. Generally speaking, the following indicators are helpful to objectively understand the magnitude of braking force: Danone effect refers to the effect that the energy released by the warhead reaches the human body after being injected into the human body. Theoretically, the higher the Danone effect, the higher the proportion of the warhead's own energy acting on the human body, and the better the braking force. After the instantaneous cavity and permanent cavity bullets enter the human body, due to the shear action of shock wave and their own kinetic energy, they often form a cavity larger than the warhead volume itself. Because the muscles of the human body are elastic, the muscles will contract and recover after the bullet passes through, so the cavity formed by the bullet passing through the human body is called instantaneous cavity, while the wound cavity formed by the bullet passing through the human body is called permanent cavity. Generally speaking, the bigger the instantaneous cavity, the greater the braking force, and the bigger the permanent cavity, the greater the harm to human body. Cavity test is an important experimental basis for studying warhead lethality. In the test, the size of the instantaneous cavity is generally determined by shooting gelatin, soap, clay glue and other objects close to the human muscle medium. Because such experimental objects are inelastic, the cavity formed after shooting is an instantaneous cavity. In order to determine the permanent cavity, it is necessary to use live experimental objects such as pigs and dogs for experiments. The size of the permanent cavity caused by bullets and the degree of damage to musculoskeletal can be determined by the trauma of experimental animals. The relationship between penetrating power and stopping power is often contradictory. If the penetrating power is too strong, it may penetrate the target after hitting the target and take away most of the energy. However, excessive pursuit of stopping power may lead to a serious decline in penetration. Therefore, it is necessary to balance the relationship between the two when designing bullets. From this, we can continue to discuss the improvement method of bullets. The warhead launched through the barrel will be propelled by the ability of propellant to explode instantly and fly in the given direction of the barrel. The shell will be separated from the warhead and left in the gun bore or thrown out of the gun bore by the recoil shell throwing mechanism. Therefore, if you want to increase the lethality of bullets, it is usually improved on propellants or warheads. Improvement of Propellant The function of propellant is to give the warhead flight energy. Obviously, the greater the energy of the propellant explosion, the greater the power of the bullet. First of all, people can improve the power of bullets by developing more propellants with energy storage. However, this is quite difficult, and the formula of propellant has not been innovated for a long time. In addition, increasing the charge of bullets is the simplest means to enhance power. In addition to shotguns, the specifications of bullets can generally be described by two main parameters. The first is the caliber, which refers to the vertical distance between two opposite public lines in the barrel of a rifled gun. The other is the length of the shell casing. The simplest way to increase the charge is to increase the caliber or length of the cartridge case. Take the 7.62 bullet as an example. Although both NATO forces and Warsaw Pact forces use 7.62 mm caliber bullets, the shell length of NATO force's 7.62 bullet is 5 1 mm, while Warsaw Pact's is 39 mm, so the power of NATO's 7.62x56438+0 bullet is much higher than that of Warsaw Pact's 7.62x39 bullet. However, it is not a good idea to blindly increase the length of the cartridge case or the caliber of ammunition, because larger bullets mean that soldiers carry less ammunition, or the recoil is too great to bear. Since the 1960s, the United States has been brewing the reform of small-caliber weapons, and started to use M 193 small-caliber rifle ammunition with specifications of 5.56x45. Therefore, it is difficult to meet the actual needs simply by increasing the charge. Basic classification Most bullets we usually see are of one color, but in fact there are many colors of bullets, such as green, red, black and white. Why? It turns out that there are many kinds of bullets and their uses are different. In order to distinguish easily in battle, the manufacturer painted the tip of the bullet with different colors. Ordinary bullets are not painted or plated with silver (steel-core bullets). It is covered with copper and a core made of steel or lead. Mainly used to kill the enemy's living target. The warhead of the tracer is painted green. The front end of the warhead is a lead core with a tracer tube in the middle. The tube is filled with luminescent agent, and there is a fixing ring at the tail to prevent the luminescent agent from flowing out. This luminous agent is composed of combustible, oxide and adhesive, so when it flies at night, there will be a bright light behind it. Tracer bombs are mainly used to display trajectory, indicate targets and shoot correctly. The warhead is painted red and the top is painted purple, which is mainly used by some large-caliber machine guns. Its structure is basically the same as that of incendiary bomb, except that the rear end inside the warhead is equipped with luminescent agent. It combines the specialties of various bullets, which can not only indicate the trajectory, but also penetrate the armor and set fire, and is mainly used for shooting at air and long-range targets. The warhead of the incendiary bomb is painted red, and the front end inside the warhead is filled with incendiary agent. There is a steel core in the middle of the warhead and a tracer behind it. Contains "kindling", which is mainly used to ignite flammable substances, such as enemy grass, wooden camouflage facilities, ammunition depots, fuel depots, assembly vehicles, etc. It can also be used to shoot some targets such as oil tanks made of thin iron sheets, and it can also achieve good results. Molotov cocktails pierced armor and painted black (some painted black and red circles). Its steel core is made of quenched high carbon steel. The bullet core is covered with a lead sleeve. Combustion agent is installed at the front end of warhead, and most products are installed at the rear end of warhead. Mainly used to shoot enemy light armored targets and fuel tanks. The warhead of the instant explosive of the armor-piercing incendiary bomb is painted white, and the middle of the warhead is filled with explosives. The front of the explosive is equipped with a detonator, a piercing tube and a detonator, and the back of the explosive is equipped with a luminous tube. This is a large caliber machine gun bullet, which is used to shoot into the air. When the warhead hits the target, it will detonate the explosive due to the penetration tube and detonator. The warhead won't explode because it doesn't encounter obstacles in the barrel. However, when the warhead leaves the muzzle and misses the target or obstacle, at a certain time, the flame of the luminous agent will also ignite the black powder inside and make the explosive explode. The anatomy and types of bullets are the general names of general extended warheads. This process is commonly known as mushroom, because the expanded warhead looks like a straw mushroom with a big head and a small body. This is a legal bullet in the United States, especially for hunting, and it is the most popular warhead. Some states also stipulate that such warheads must be used for hunting, because they can achieve fatal results and reduce the suffering of animals. Unlike explosive warheads commonly called Dumdums, short bullets should not break after entering the target. Of course, if it hits the bone, it won't happen. But in short, it won't break into countless small shrapnel after hitting the target like Damme. The so-called Damm tracer bomb was first produced by the British at Damm Arsenal in India in 1896. Its official name is "Dum Dum Mark 2 Special", its caliber is 303 inches, its lead core is exposed at the tip, and it looks like a modern soft-headed bullet. Due to the restrictions of the Hague International War Convention, production was stopped. Britain also used short bullets in the Boer War in South Africa (Boer War, 1899- 1902). Empty shell is a kind of bullet without bullet, that is, it is only composed of primer, shell and propellant. The shell of an empty bullet is longer than that of an ordinary bullet, and it is sealed by mechanical pressing after being filled with propellant. Empty bombs are mainly used for military exercises and wartime Grenade launches. When shooting movies and TV series about war and police robbers, bullets are also used in large numbers instead of ordinary bullets to avoid accidents. In 20 10, the US military used the new XM25 rifle to launch smart bombs on the battlefield in Afghanistan for the first time. It is equipped with a smart chip, which can receive wireless signals. After launch, it is controlled by a predetermined program and detonated when it flies to a certain distance. Compared with the traditional metal shell, shellless is "shellless". Propellant is packed with highly flammable adhesive, which is pressed into powder column, and warhead and primer are embedded at both ends of powder column respectively. There is no metal shell packaging. Liquid bullets Liquid bullets don't mean that bullets are liquid, but that propellants are liquid. When shooting, liquid propellant is injected into the combustion chamber by the compression pump on the gun, and then the warhead is fired. It is characterized by lighter ammunition, which helps to reduce the weight of weapon system. Multi-warhead and multi-warhead, as the name implies, means that a bullet has two or more similar warheads, and firing several warheads at a time (usually 3 ~ 5) is equivalent to firing several bullets at the same time, which can significantly improve the firepower intensity. The air explosive bomb developed by the US Army is characterized in that it can explode over the heads of enemy soldiers in bunkers, spraying deadly metal fragments, leaving them nowhere to hide. There are electronic fuzes and sensors inside the bullet, which can track weak light and thermal radiation and can be used at night. In 20 10, the US Marine Corps used this kind of reinforced bomb in the battlefield of Afghanistan. Its scientific name is "SOST". Its biggest feature is its open design and lead core, which makes the warhead more powerful and has a longer range. It is called "the obstacle is invalid", that is to say, after penetrating obstacles such as glass and walls, the hit accuracy and lethality are still high. The nickname "dirty Harry" developed by the British army also belongs to this type of bullet. Special bullets paralyze people's hearing and central nervous system through the noise wave emitted by the explosion, which makes people unconscious in a short time. Life-saving bombs are filled with sedatives and first-aid drugs. When a soldier is injured or dying and the medical staff can't get close to him, fire bullets for first aid to keep his life. As long as the fire extinguisher is put into the flame, it will explode immediately, and a large amount of carbon dioxide will be released in the bomb, which will soon put out the fire. The eavesdropping bomb is only 1 cm in diameter and is fired with a gun. It is equipped with UHF transmitter and microelectronic instrument, which can eavesdrop on Fiona Fang's conversation for several meters and detect various trends, and can be used for reconnaissance in war or complex situations. Improvement of warhead Besides charging, the improvement of warhead has always been an important measure to increase the lethality of bullets. The cost of improving the warhead is far lower than that of improving the propellant and increasing the charge-because the same firearm can't fire bullets with different calibers or shell lengths without modification. Once modified, it means that the whole army must replace the firearms and ammunition reserves to cooperate, and this cost is very high. In fact, since World War II, NATO and Warsaw Pact countries have only changed their ammunition caliber once after unifying their respective ammunition systems. Therefore, tapping the potential of bullets on warheads is the lowest cost way to increase the lethality of existing ammunition. There are several ways to increase the lethality of warhead to human body: increase the mass of warhead. Theoretically, the greater the mass of the warhead, the higher the energy at the same speed, the higher the braking force on the human body, and the better the speed after a long flight. Therefore, the use of heavy warheads is a necessary means to increase the lethality of bullets. On the battlefields of Iraq and Afghanistan, the US special forces changed into new M262 5.56 rifle bullets. The warhead weight of this bullet is 77 grains (equivalent to 4.98 grams), which is nearly 24% higher than the original ss 109 bullet's 4.02 grams. The braking force of the target has been obviously improved, and it is often used in urban clearance operations. Changing the shape of warhead has a direct impact on lethality. For example, in order to improve the penetration ability, it is necessary to increase the cross-sectional area density of warheads. Simply put, the sharper the bullet, the harder the material used in the warhead, and the stronger the penetration. Therefore, rifle bullets that need a long range and have a certain ability to penetrate bulletproof vests, bunkers and other objects must be streamlined pointed bullets, and hard metals such as steel cores are often used to increase the bullet density to achieve higher penetration. On the contrary, round-headed or flat-headed projectiles have weak penetrating power, but strong blocking power, and Danone has better effect. Therefore, changing the shape of the warhead can improve the lethality of the bullet with the same caliber and charge. Generally speaking, changing the material of the warhead can increase the penetration of the bullet by using bullets with higher density and hardness, while using soft materials may increase the braking force of the bullet. However, because most bullets are armored bullets, even soft materials may not give full play to their material characteristics because of armored bullets. In short, different materials of bullets have different effects on the lethality of bullets. The bullet of this design is produced purely to increase the braking force of the bullet. If the penetration is too strong, the bullet may pass through the human body, and a lot of energy does not act on the human body. However, if the bullet bursts, expands or shatters after entering the human body, most of the kinetic energy contained in the bullet can be released into the human body, accelerating the disability of the hit target. Increase instability, so that it will roll and lose stability after entering the human body. The bullet of this design is also produced to increase the braking force of the bullet. The principle is to obtain a stronger Danone effect through the tumbling and instability of bullets entering the human body. The so-called bullet tumbling means that when the bullet moves, it makes a spiral rotation motion with the forward direction as the axis. Instability means that the bullet no longer moves along the original parabola after entering the human body, and becomes extremely unstable, and will change direction when touching any object. The tumbling bullet will cause more trauma to the human body, and the unstable bullet will inevitably cause a longer stroke in the body, because the shortest straight line between two points is a straight line. However, unstable bullets often move in an S-shaped line, and the bullets travel farther through the human body, which may cause more organ, internal organs and tissue damage. There is a saying that automatic fire extinguishing catapults into the air. "When they go up, there will be a time to fall back." If you shoot into the air, the bullet can fly at most 1.5km (depending on the shooting angle and the performance of the gun, the kinetic energy generated by the bullet landing beyond a certain angle can only cause minor injuries). After reaching the highest point, the bullet will start to fall. Although the air resistance limits the flying speed of the bullet to a certain extent, because the shape of the bullet is aerodynamically designed, the falling speed is still fatal (if it happens to fall on someone). In rural areas, the probability of falling bullets hitting people is very low, because the population density there is low. In crowded cities, the probability of falling bullets hitting people is greatly increased, and people often die from stray bullets. So most big cities have laws prohibiting people from shooting in the air during celebrations. There is no doubt that as long as the bullets fired at the earth travel in a curved route. Because of the influence of the earth's gravity, any object thrown or launched will follow a parabola, but the elevation angle is different and the radian is different, but the essence of parabola will not change. In order to overcome the influence of parabola, military rifles used by troops must be set with different heights of gauge to aim at targets at different distances. Another important concept of shooting is high trajectory. Simply put, it is how far the bullet is above the muzzle. This is very important for aiming, because the bullet is a parabola, but the light is a straight line, and the line of sight from your eyes to the target is a straight line, so when aiming at a long-distance target, you must calculate the accurate distance to know where the coincidence point of the line of sight and the trajectory is. Another very important concept in aiming is zeroing. The so-called zero adjustment is to adjust the gun aiming so that the launched warhead can correctly hit the aiming point at a specific distance. Once the zero adjustment is completed at a certain distance, you can hit the aiming point at other distances simply by adjusting the scale on the gun aiming. Because there are differences between each gun, it is best to return to zero before each shot. Strictly speaking, even there are considerable differences between each batch of ammunition, so when snipers get a new batch of ammunition, they usually zero it and use it until they run out. Simply put, the use of different bullets or different guns may lead to subtle changes in the trajectory of bullets. For example, the arc of a trajectory may be slightly different. If it is necessary to shoot at a long distance, it is necessary to determine what the arc drawn by the bullet in the air looks like by returning to zero before hitting the target. In "Wanted Order", the killer's common weapon is a pistol, and most pistols have no gauge to adjust the ballistic height, so it is necessary to choose aiming points higher or lower than the target at different distances to adjust the ballistic height. Some people think that theoretically, if the wrist swing speed is close to the initial velocity of the bullet, it may affect the trajectory and send out a curved ball similar to the banana ball in football, thus achieving the effect in the movie "Wanted Order". However, in fact, this is impossible. First of all, the banana ball of football can not be formed entirely because of the movement of beriberi. But because of the magnus effect. Because football is an elastic object, its motion is suitable for hydrodynamic effect. In fluid mechanics, if a cylinder rotating around an axis moves laterally, it will bear the force perpendicular to the direction of movement given by the fluid. This phenomenon is called Magnus effect. In ball games, Magnus effect can be used to make the ball drift laterally. If the resultant force of hitting the ball does not pass through the center of the ball, the ball will move forward and rotate at the same time. Because of Magnus effect, the ball will drift laterally in the process of progress, resulting in curved balls such as banana balls. Because the bullet is a solid weapon, Magnus effect is very small, and it is impossible to produce an exaggerated arc as in the film. Moreover, the firearms used in the film are all rifled guns, and the bullets of the rifled guns themselves rotate by rifling after being launched. Rotation produces gyro stability, which makes bullets more stable than objects that can't rotate during flight. Therefore, swinging the wrist may make the bullet miss the target, but it is impossible to have an exaggerated arc motion like the wanted order, and it is even more impossible to see the situation that Angelina Jolie's bullet at the end of the film starts from the origin and makes a circle around the field, killing everyone and then returning to the origin.