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5.45×39mm Assault Rifles
The 5.45×39mm Cartridge (firearms), cartridge is a Rim (firearms), 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. History The 5.45×39mm cartridge was developed in the early 1970s by a group of Soviet designers and engineers under the direction of M. Sabelnikov. Further group members were: L. I. Bulavsky, B. B. Semin, M. E. Fedorov, P. F. Sazonov, V. Volkov, V. A. Nikolaev, E. E. Zimin and P. S. Korolev. The 5.45×39mm couples a sensible case volume (1.75 ml) to bore area (23.99 mm2/0.2399 cm2) Overbore, ratio with ample space for loading relatively long slender projectiles that can provide good aerodynamic efficiency and external ballistic performance for the projectile diameter. The 5.45×39mm is an example of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soviet Union
The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet Union, it dissolved in 1991. During its existence, it was the list of countries and dependencies by area, largest country by area, extending across Time in Russia, eleven time zones and sharing Geography of the Soviet Union#Borders and neighbors, borders with twelve countries, and the List of countries and dependencies by population, third-most populous country. An overall successor to the Russian Empire, it was nominally organized as a federal union of Republics of the Soviet Union, national republics, the largest and most populous of which was the Russian SFSR. In practice, Government of the Soviet Union, its government and Economy of the Soviet Union, economy were Soviet-type economic planning, highly centralized. As a one-party state go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cartridge (firearms)
A cartridge, also known as a round, is a type of pre-assembled firearm ammunition packaging a projectile ( bullet, shot, or slug), a propellant substance ( smokeless powder, black powder substitute, or black powder) and an ignition device ( primer) within a metallic, paper, or plastic case that is precisely made to fit within the barrel chamber of a breechloading gun, for convenient transportation and handling during shooting. Although in popular usage the term "bullet" is often used to refer to a complete cartridge, the correct usage only refers to the projectile. Military and commercial producers continue to pursue the goal of caseless ammunition. Some artillery ammunition uses the same cartridge concept as found in small arms. In other cases, the artillery shell is separate from the propellant charge. A cartridge without a projectile is called a '' blank''; one that is completely inert (contains no active primer and no propellant) is called a '' dummy''; one that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drag (physics)
In fluid dynamics, drag, sometimes referred to as fluid resistance, is a force acting opposite to the direction of motion of any object moving with respect to a surrounding fluid. This can exist between two fluid layers, two solid surfaces, or between a fluid and a solid surface. Drag forces tend to decrease fluid velocity relative to the solid object in the fluid's path. Unlike other resistive forces, drag force depends on velocity. Drag force is proportional to the relative velocity for low-speed flow and is proportional to the velocity squared for high-speed flow. This distinction between low and high-speed flow is measured by the Reynolds number. Drag is instantaneously related to vorticity dynamics through the Josephson-Anderson relation. Examples Examples of drag include: * Net force, Net Aerodynamic force, aerodynamic or Fluid dynamics, hydrodynamic force: Drag acting opposite to the direction of movement of a solid object such as cars, aircraft, and boat hulls. * Viscou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead
Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable nuclide, stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its Amphoterism, amphoteric nature; lead and lead oxides react with acids and base (chemistry), bases, and it tends to form covalent bonds. Lead compounds, Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are mostly limited ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilding Metal
Gilding metal is a form of brass (an alloy of copper and zinc) with a much higher copper content than zinc content. Exact figures range from 95% copper and 5% zinc to “8 parts copper to 1 of zinc” (11% zinc) in British Army Dress Regulations. Gilding metal is used for various purposes, including the jackets of bullets, driving bands on some artillery shells, as well as enameled badges and other jewellery. The sheet is widely used for craft metalworking by hammer working. It is also used particularly as a lower-cost training material for silversmiths. Starting in 1944, shell casings made of gilding metal were melted down by the United States Mint to be made into pennies. These pennies replaced the less popular steel cent of 1943, and the pennies of this composition were produced until 1946. Gilding metal was also used for the "bronze" Olympic medal at the 2020 Summer Olympics The officially the and officially branded as were an international multi-sport eve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Recoil
Free recoil / Frecoil is a vernacular term or jargon for recoil energy of a firearm not supported from behind. Free recoil denotes the translational kinetic energy (''Et'') imparted to the shooter of a small arm when discharged and is expressed in joules (J), or foot-pound force (ft·lb''f'') for non-SI units of measure. More generally, the term refers to the recoil of a free-standing firearm, in contrast to a firearm securely bolted to or braced by a massive mount or wall. Free recoil should not be confused with recoil: * Free recoil is the given name for translational kinetic energy transmitted from a small arm to a shooter. * Recoil is a name given for conservation of momentum as it generally applies to an everyday event. Free recoil and firearms Free recoil, sometimes called ''recoil energy'', is a byproduct of the propulsive force from the powder charge held within a firearm chamber ( metallic cartridge firearm) or breech (gunpowder firearm). The physical event of free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolt Thrust
Bolt thrust or breech pressure is a term used in internal ballistics and firearms (whether small arms or artillery) that describes the amount of rearward force exerted by the propellant gases on the Bolt (firearms), bolt or Breechblock, breech of a firearm action or Breech-loading weapon, breech when a projectile is fired. The applied force has both Euclidean vector#Length, magnitude and Direction (geometry, geography), direction, making it a Vector (geometric), vector quantity. Bolt thrust is an important factor in weapons design. The greater the bolt thrust, the stronger the locking mechanism has to be to withstand it. Assuming equal engineering solutions and material, adding strength to a locking mechanism causes an increase in weight and size of locking mechanism components. Bolt thrust is not a measure to determine the amount of recoil or free recoil. Calculating bolt thrust With a basic calculation the bolt thrust produced by a particular firearms cartridge can be calculated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Point-blank Range
Point-blank range is any distance over which a certain firearm or gun can hit a target without the need to elevate the barrel to compensate for bullet drop, i.e. the gun can be pointed horizontally at the target. For targets beyond-blank range, the shooter will have to point the barrel of their firearm at a position above the target, and firearms that are designed for long range firefights usually have adjustable sights to help the shooter hit targets beyond point-blank range. The maximum point-blank range of a firearm will depend on a variety of factors such as muzzle velocity and the size of the target. In popular usage, point-blank range has come to mean extremely close range with a firearm, yet not close enough to be a contact shot. Point-blank (when describing a person) means direct or blunt. History The term ''point-blank'' dates to the 1570s and is probably of French origin, deriving from , "pointed at white". It is thought the word ''blanc'' may be used to describe a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overbore
Overbore cartridges are those with a relatively large case volume or case capacity, coupled with a relatively small diameter bullet. The case volume or case capacity and barrel bore area can be mathematically related to obtain a case volume to bore area ratio in metric or imperial units. = \frac where: * Volume_ = the cartridge case internal volume or case capacity (in ml or (for non-metric users) grains of water) * Area_ = barrel bore cross section area (in cm2 or in2) The higher the Oratio result, the more overbore a cartridge will be. As the ratio is expressed in units of length, relatively high Oratio is a good predictor of suitability for relatively long barreled guns. Oratio is also used to predict barrel life in cartridges of the same caliber, but not of different calibres, since the ratio is an extensive quantity that does not correlate to temperature or pressure (e.g. a .50 cal straight cartridge may have the same overbore as a highly necked down .17 cal cartridge). Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comparison Of Cold War Ammunition Rotated
Comparison or comparing is the act of evaluating two or more things by determining the relevant, comparable characteristics of each thing, and then determining which characteristics of each are similar to the other, which are different, and to what degree. Where characteristics are different, the differences may then be evaluated to determine which thing is best suited for a particular purpose. The description of similarities and differences found between the two things is also called a comparison. Comparison can take many distinct forms, varying by field: To compare things, they must have characteristics that are similar enough in relevant ways to merit comparison. If two things are too different to compare in a useful way, an attempt to compare them is colloquially referred to in English as "comparing apples and oranges." Comparison is widely used in society, in science and the arts. General usage Comparison is a natural activity, which even animals engage in when decidin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Service Rifle
A service rifle (or standard-issue rifle) is a rifle a military issues to its regular infantry. In modern militaries, this is generally a versatile, rugged, and reliable assault rifle or battle rifle, suitable for use in nearly all environments and is effective in most combat situations. Almost all modern militaries are issued service pistols as sidearms to accompany their service rifles. The term can also be used to describe weapons issued by non-military forces, such as law enforcement or paramilitaries. If the issued weapon is not a rifle or carbine, but instead a different type of firearm intended to serve in a specialized role such as a combat shotgun, submachine gun, or light machine gun, it is called a service firearm or service weapon. History Firearms with rifled barrels existed long before the 19th century, but were not widely used until the mid-19th century in conflicts such as the Crimean War and American Civil War. Thus, rifles in the early 19th century were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
