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Physics Of Firearms
From the viewpoint of physics ( dynamics, to be exact), a firearm, as for most weapons, is a system for delivering maximum destructive energy to the target with minimum delivery of energy on the shooter. The momentum delivered to the target, however, cannot be any more than that (due to recoil) on the shooter. This is due to conservation of momentum, which dictates that the momentum imparted to the bullet is equal and opposite to that imparted to the gun-shooter system. Firearm energy efficiency From a thermodynamic point of view, a firearm is a special type of piston engine, or in general heat engine where the bullet has a function of a piston. The energy conversion efficiency of a firearm strongly depends on its construction, especially on its caliber and barrel length. However, for illustration, here is the energy balance of a typical small firearm for .300 Hawk ammunition: *Barrel friction 2% *Projectile motion 32% *Hot gases 34% *Barrel heat 30% *Unburned propellant 1%. whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penetration (weapons)
Strictly speaking, penetration occurs when a projectile enters a target without passing through it and perforation occurs when the projectile completely passes through the target, but the word ''penetration'' is commonly used to refer to either. Penetration into a ''semi-infinite'' or ''massive'' target is penetration (in the strict sense of the word) of targets so thick that the level of penetration is not affected by the target's thickness. There is a ''transition region'' between semi-infinite penetration and perforation, in which the target is not perforated but the projectile, as it nears the back face of the target, meets reduced resistance and is capable of penetrating a greater distance than it would in a semi-infinite target. This effect is variously named the back or rear surface, plate, or face effect and is also present when perforation occurs. A penetrating projectile may cause the target to break into multiple pieces, spewing from both the front and back of the targ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firearms
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears to make the portable fire lance, operable by a single person, which was later used effectively as a shock weapon in the Siege of De'an in 1132. In the 13th century, fire lance barrels were replaced with metal tubes and transformed into the metal-barreled hand cannon. The technology gradually spread throughout Eurasia during the 14th century. Older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other propellants. Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart spin to the projectile for improved flight stability. Modern firearms can be described by their caliber (i.e. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Of Handgun And Rifle Cartridges
This is a table of selected pistol/submachine gun and rifle/machine gun cartridges by common name. Data values are the highest found for the cartridge, and might not occur in the same load (e.g. the highest muzzle energy might not be in the same load as the highest muzzle velocity, since the bullet weights can differ between loads). Legend * Factory loadings. Number of manufacturers currently producing complete cartridges - e.g. Norma, RWS, Hornady, Winchester, Federal, Remington, Sellier & Bellot, Prvi Partizan. May be none for obsolete and wildcat cartridges. * H/R: Handgun (H) or rifle (R) - dominant usage of the cartridge (although several dual-purpose cartridges exist) * Size: Metric size - may not be official * MV: Muzzle velocity, in feet-per-second * ME: Muzzle energy, in foot-pounds * P: Momentum, in pound (force) (lbf) times seconds. A guide to the recoil from the cartridge, and an indicator of bullet penetration potential. The .30-06 Springfield (at 2.064 lbf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Ballistics
External ballistics or exterior ballistics is the part of ballistics that deals with the behavior of a projectile in flight. The projectile may be powered or un-powered, guided or unguided, spin or fin stabilized, flying through an atmosphere or in the vacuum of space, but most certainly flying under the influence of a gravitational field. Gun-launched projectiles may be unpowered, deriving all their velocity from the propellant's ignition until the projectile exits the gun barrel. However, exterior ballistics analysis also deals with the trajectories of rocket-assisted gun-launched projectiles and gun-launched rockets; and rockets that acquire all their trajectory velocity from the interior ballistics of their on-board propulsion system, either a rocket motor or air-breathing engine, both during their boost phase and after motor burnout. External ballistics is also concerned with the free-flight of other projectiles, such as balls, arrows etc. Forces acting on the projectile W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Internal Ballistics
Internal ballistics (also interior ballistics), a subfield of ballistics, is the study of the propulsion of a projectile. In guns, internal ballistics covers the time from the propellant's ignition until the projectile exits the gun barrel. The study of internal ballistics is important to designers and users of firearms of all types, from small-bore rifles and pistols, to high-tech artillery. For rocket-propelled projectiles, internal ballistics covers the period during which a rocket motor is providing thrust. Parts and equations Hatcher breaks the duration of interior ballistics into three parts: *Lock time, the time from sear release until the primer is struck *Ignition time, the time from when the primer is struck until the projectile starts to move *Barrel time, the time from when the projectile starts to move until it exits the barrel. There are many processes that are significant. The source of energy is the burning propellant. It generates hot gases that raise the chambe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistics
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. A ballistic body is a free-moving body with momentum which can be subject to forces such as the forces exerted by pressurized gases from a gun barrel or a propelling nozzle, normal force by rifling, and gravity and air drag during flight. A ballistic missile is a missile that is guided only during the relatively brief initial phase of powered flight and the trajectory is subsequently governed by the laws of classical mechanics; in contrast to (for example) a cruise missile which is aerodynamically guided in powered flight like a fixed-wing aircraft. History and prehistory The earliest known ballistic projectiles were stones and spears, and the throwing stick. The oldes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contusion
A bruise, also known as a contusion, is a type of hematoma of tissue, the most common cause being capillaries damaged by trauma, causing localized bleeding that extravasates into the surrounding interstitial tissues. Most bruises occur close enough to the epidermis such that the bleeding causes a visible discoloration. The bruise then remains visible until the blood is either absorbed by tissues or cleared by immune system action. Bruises which do not blanch under pressure can involve capillaries at the level of skin, subcutaneous tissue, muscle, or bone. Bruises are not to be confused with other similar-looking lesions. (Such lesions include petechia (less than , resulting from numerous and diverse etiologies such as adverse reactions from medications such as warfarin, straining, asphyxiation, platelet disorders and diseases such as '' cytomegalovirus''), purpura (, classified as palpable purpura or non-palpable purpura and indicates various pathologic conditions such as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twaron
Twaron (a brand name of Teijin Aramid) is a para-aramid. It is a heat-resistant and strong synthetic fibre developed in the early 1970s by the Dutch company Akzo Nobel's division Enka BV, later Akzo Industrial Fibers. The research name of the para-aramid fibre was originally Fiber X, but it was soon called Arenka. Although the Dutch para-aramid fiber was developed only a little later than DuPont's Kevlar, the introduction of Twaron as a commercial product came much later than Kevlar due to financial problems at the AKZO company in the 1970s. History This is a chronology of the development of Twaron: * In 1960s a research program starts for "Fiber X." * In 1972 the ENKA Research laboratory develops a para-aramid called Arenka. * In 1973 Akzo decides to use sulfuric acid (H2SO4) as a solvent for spinning. * In 1974 New process route was found at Akzo Research laboratory, using N-methylpyrrolidone (NMP) with a co-solvent (auxiliary solvent) with an ionic component (Calcium Chloride ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kevlar
Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires. It is typically spun into ropes or fabric sheets that can be used as such, or as an ingredient in composite material components. Kevlar has many applications, ranging from bicycle tires and racing sails to bulletproof vests, all due to its high tensile strength-to-weight ratio; by this measure it is five times stronger than steel. It is also used to make modern marching drumheads that withstand high impact; and for mooring lines and other underwater applications. A similar fiber called Twaron with the same chemical structure was developed by Akzo in the 1970s; commercial production started in 1986, and Twaron is now manufactured by Teijin. History Poly-paraphenylene terephthalamide (K2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aramid
Aramid fibers, short for aromatic polyamide, are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic-rated body armor fabric and ballistic composites, in marine cordage, marine hull reinforcement, and as an asbestos substitute. The chain molecules in the fibers are highly oriented along the fiber axis. As a result, a higher proportion of the chemical bond contributes more to fiber strength than in many other synthetic fibers. Aramids have a very high melting point (>500 °C). Common aramid brand names include Kevlar, Nomex, and Twaron. Terminology and chemical structure ''Aramid'' is a shortened form of aromatic polyamide. The term was introduced in 1972, accepted in 1974 by the Federal Trade Commission of the USA as the name of a generic category of fiber distinct from nylon, and adopted by the International Standards Organisation in 1977. Aromatic in the name refers to the presence of aromatic rings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
