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Subsonic Ammunition
Subsonic ammunition is ammunition designed to operate at velocities below the speed of sound (Mach 1), which at standard conditions is . This avoids the supersonic shockwave or "crack" of a supersonic bullet, which, particularly for suppressed firearms, influences the loudness of the shot.Shooting Range Industries. Shooting Terms; What Is Bullet Drag, Bow Shockwave, Mach Speed Number, Boat Tail & More - Shooting Range Industries. nlineAvailable at: Subsonic ammunition usually uses heavier bullets to retain as much kinetic energy as possible at the lower velocities. Some subsonic ammunition is used in non-suppressed firearms to gain the advantages of heavier bullet weights. __TOC__ Standard calibers Subsonic versions of standard rounds In this instance, heavier bullets are loaded in standard ammunition, which reduces muzzle velocity below the speed of sound. As an example, the very common 9×19mm Parabellum standard military round is a bullet at velocities typically around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammunition
Ammunition, also known as ammo, is the material fired, scattered, dropped, or detonated from any weapon or weapon system. The term includes both expendable weapons (e.g., bombs, missiles, grenades, land mines), and the component parts of other weapons that create the effect on a target (e.g., bullets and warheads). The purpose of ammunition is to project a force against a selected Targeting (warfare), target to have an effect (usually, but not always, lethal). An example of ammunition is the firearm Cartridge (firearms), cartridge, which includes all components required to deliver the weapon effect in a single package. Until the 20th century, black powder was the most common propellant used but has now been replaced in nearly all cases by modern compounds. Ammunition comes in a great range of sizes and types and is often designed to work only in specific weapons systems. However, there are internationally recognized standards for certain ammunition types (e.g., 5.56×45mm NA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Of Sound
The speed of sound is the distance travelled per unit of time by a sound wave as it propagates through an elasticity (solid mechanics), elastic medium. More simply, the speed of sound is how fast vibrations travel. At , the speed of sound in air is about , or in or one mile in . It depends strongly on temperature as well as the medium through which a sound wave is propagating. At , the speed of sound in dry air (sea level 14.7 psi) is about . The speed of sound in an ideal gas depends only on its temperature and composition. The speed has a weak dependence on frequency and pressure in dry air, deviating slightly from ideal behavior. In colloquial speech, ''speed of sound'' refers to the speed of sound waves in Earth's atmosphere, air. However, the speed of sound varies from substance to substance: typically, sound travels most slowly in gases, faster in liquids, and fastest in solids. For example, while sound travels at in air, it travels at in water (almost 4.3 times a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mach Number
The Mach number (M or Ma), often only Mach, (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a boundary to the local speed of sound. It is named after the Austrian physicist and philosopher Ernst Mach. \mathrm = \frac, where: * is the local Mach number, * is the local flow velocity with respect to the boundaries (either internal, such as an object immersed in the flow, or external, like a channel), and * is the speed of sound in the medium, which in air varies with the square root of the thermodynamic temperature. By definition, at Mach1, the local flow velocity is equal to the speed of sound. At Mach0.65, is 65% of the speed of sound (subsonic), and, at Mach1.35, is 35% faster than the speed of sound (supersonic). The local speed of sound, and hence the Mach number, depends on the temperature of the surrounding gas. The Mach number is primarily used to determine the approximation with which a flow can be treated as an i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonic Boom
A sonic boom is a sound associated with shock waves created when an object travels through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding similar to an explosion or a thunderclap to the human ear. The crack of a supersonic bullet passing overhead or the crack of a bullwhip are examples of a small sonic boom. Sonic booms due to large supersonic aircraft can be particularly loud and startling, tend to awaken people, and may cause minor damage to some structures. This led to the prohibition of routine supersonic flight overland. Although sonic booms cannot be completely prevented, research suggests that with careful shaping of the vehicle, the nuisance due to sonic booms may be reduced to the point that overland supersonic flight may become a feasible option. A sonic boom does not occur only at the moment an object crosses the sound barrier and neither is it heard in all directions emanating from the supersonic objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suppressor
A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a gun barrel#Muzzle, muzzle device that suppresses the muzzle blast, blast created when a gun (firearm or airgun) is discharged, thereby reducing the sound intensity, acoustic intensity of the muzzle report (sound of a gunshot) and muzzle rise, jump, by modulating the speed and pressure of the propellant gas released from the muzzle. Like other muzzle devices, a silencer can be a detachable accessory mounted to the muzzle or an integral part of the gun barrel, barrel. A typical silencer is a metallic (usually stainless steel or titanium) cylinder (firearms), cylinder containing numerous internal sound baffles, with a hollow bore to allow the bullet to exit normally. During firing, the bullet passes through the bore with little hindrance, but most of the expanding gas ejecta behind it is redirected through a longer and convoluted escape path created by the baffles, prolonging the release time. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
9×19mm Parabellum
The 9×19mm Parabellum (also known as 9mm Luger, 9mm NATO or simply 9mm) is a Rim (firearms)#Rimless, rimless, Centerfire ammunition, centerfire, tapered cartridge (firearms), firearms cartridge. Originally designed by Austrian firearm designer Georg Luger in 1901, it is widely considered the most popular handgun and submachine gun cartridge due to its low cost, adequate stopping power and extensive availability. Since the cartridge was designed for the Luger pistol, Luger semi-automatic pistol, it has been given the designation of ''9mm Luger'' by the Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) and the (CIP). A 2007 US survey concluded that "about 60 percent of the firearms in use by police are 9mm [Parabellum]" and credited 9×19mm Parabellum pistol sales with making semiautomatic pistols more popular than revolvers.Adler, Jerry, et al. (30 April 2007)"Story of a Gun"(). ''Newsweek'' 149.18: 36–39. MasterFILE Premier. EBSCO. Dallas Public Library, Dallas, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semi-automatic Firearm
A semi-automatic firearm, also called a self-loading or autoloading firearm ( fully automatic and selective fire firearms are also variations on self-loading firearms), is a repeating firearm whose action mechanism automatically loads a following round of cartridge into the chamber and prepares it for subsequent firing, but requires the shooter to manually actuate the trigger in order to discharge each shot. Typically, this involves the weapon's action utilizing the excess energy released during the preceding shot (in the form of recoil or high-pressure gas expanding within the bore) to unlock and move the bolt, extracting and ejecting the spent cartridge case from the chamber, re-cocking the firing mechanism, and loading a new cartridge into the firing chamber, all without input from the user. To fire again, however, the user must actively release the trigger, and allow it to "reset", before pulling the trigger again to fire off the next round. As a result, each trigger p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
45 ACP
The .45 ACP (Automatic Colt Pistol), also known as .45 Auto, .45 Automatic, or 11.43×23mm is a Rim (firearms)#Rimless, rimless straight-walled handgun Cartridge (firearms), cartridge designed by John Moses Browning in 1904, for use in his prototype Colt's Manufacturing Company, Colt semi-automatic pistol. After successful military trials, it was adopted as the standard chambering for Colt's M1911 pistol. The round was developed due to a lack of stopping power experienced in the Moro Rebellion in places like Sulu. The issued ammunition, .38 Long Colt, had proved inadequate, motivating the search for a better cartridge. This experience and the Thompson–LaGarde Tests of 1904 led the Army and the Cavalry to decide that a minimum of .45 caliber was required in a new handgun cartridge. The standard-issue military .45 ACP cartridge uses a round-nose bullet at approximately fired from a government-issue M1911A1 pistol. It operates at a relatively low maximum chamber pressure rating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
300 Whisper
3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious and cultural significance in many societies. Evolution of the Arabic digit The use of three lines to denote the number 3 occurred in many writing systems, including some (like Roman and Chinese numerals) that are still in use. That was also the original representation of 3 in the Brahmic (Indian) numerical notation, its earliest forms aligned vertically. However, during the Gupta Empire the sign was modified by the addition of a curve on each line. The Nāgarī script rotated the lines clockwise, so they appeared horizontally, and ended each line with a short downward stroke on the right. In cursive script, the three strokes were eventually connected to form a glyph resembling a with an additional stroke at the bottom: ३. The Indian digits spread to the Caliphate in the 9th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
300 AAC Blackout
The .300 AAC Blackout (abbreviated as 300 BLK by the SAAMI and 300 AAC Blackout by the C.I.P.), also known as 7.62×35 mm, is an intermediate cartridge developed in the United States by Advanced Armament Corporation (AAC) for use in the M4 carbine. The cartridge yields increased performance in shorter barrels and effective subsonic performance for silencer use when compared to 5.56 mm NATO. The .300 AAC Blackout uses standard 5.56 mm NATO magazines and components with the exception of the barrel. History Although 5.56×45mm NATO has been widely adopted in the NATO armies, the nature of the missions encountered by some special operations groups often requires a round that provides better performance than that available in the high-energy, standard velocity rounds, and subsonic performance greater than standard 9×19mm Parabellum (the ubiquitous pistol and submachine gun round). To meet this demand, AAC developed the .300 AAC Blackout in cooperation with Remington Defense. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
338 Whisper
__NOTOC__ Year 338 ( CCCXXXVIII) was a common year starting on Sunday of the Julian calendar. At the time, it was known as the Year of the Consulship of Ursus and Polemius (or, less frequently, year 1091 ''Ab urbe condita''). The denomination 338 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * The Romans, allied with the Goths, arrive in the north of the Roman Empire to protect the Danube frontier. * Emperor Constantius II intervenes against the Persians in Armenia. Persia * Shapur II, king of the Persian Empire, begins a widespread persecution of Christians. He orders forcible conversions to the state religion, Zoroastrianism, lest the Christians disrupt his realm while he is away fighting the Romans in Armenia and Mesopotamia. Asia * Tuoba Yihuai, ruler of the Tuoba Dai (Sixteen Kingdoms), Dai clan, dies and is succeeded by his br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
