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Muzzle Shroud
A muzzle shroud, linear compensator, blast shield, forward blast diverter or concussion reduction device (CRD) is a sleeve (either circular or otherwise) that attaches to and extends beyond the muzzle of a firearm in order to redirect some of the noise and concussion, or shock wave, from the muzzle blast forward and away from the shooter, and other bystanders, behind and to the sides. A muzzle shroud is similar to a barrel shroud with the difference being that it only surrounds the far end of the barrel ( muzzle). It can be a muzzle extension or muzzle device, and can also be considered a flash suppressor without circumferential openings. A muzzle shroud differs from a silencer (sound suppressor) in that its primary function is not to suppress the sound, but merely redirect it so to increase the comfort of the shooter, reducing the concussion to a comfortable level. Linear compensators are also a form of muzzle shrouds. While most muzzle brakes redirect the gases to the side ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MG42-1
MG4 may refer to: *Heckler & Koch MG4, MG4, Heckler & Koch firearm *British NVC community MG4, MG4, British NVC community category * MG4 (album), ''MG4'' (album) * MG4 EV, an electric car {{Letter-NumberCombDisambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Waves
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of to . Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges. Acoustics Acoustics is the interdisciplinary science that deals with the study of mechanical waves in gasses, liquids, and solids including vibration, sound, ultrasound, and infrasound. A scientist who works in the field of acoustics is an ''acoustician'', while someone working in the field of acoustical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Suppressor
A silencer, also known as a sound suppressor, suppressor, or sound moderator, is a muzzle device that reduces the acoustic intensity of the muzzle report (sound of a gunshot) and muzzle rise when a gun (firearm or air gun) is discharged, by modulating the speed and pressure of the propellant gas from the muzzle and hence suppressing the muzzle blast. Like other muzzle devices, a silencer can be a detachable accessory mounted to the muzzle, or an integral part of the barrel. A typical silencer is a metallic (usually stainless steel or titanium) cylinder containing internal sound baffles, with a hollow bore to allow the projectile (bullet) to exit normally. During firing, the bullet flies through the bore with little hindrance, but most of the expanding gas ejecta behind it is retained through a longer and convoluted escape path created by the baffles, prolonging the release time. This slows down the gas and dissipates its kinetic energy into a larger surface area, reduci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bureau Of Alcohol, Tobacco, Firearms And Explosives
The Bureau of Alcohol, Tobacco, Firearms and Explosives (BATFE), commonly referred to as the ATF, is a domestic law enforcement agency within the United States Department of Justice. Its responsibilities include the investigation and prevention of federal offenses involving the unlawful use, manufacture, and possession of firearms and explosives; acts of arson and bombings; and illegal trafficking and tax evasion of alcohol and tobacco products. The ATF also regulates via licensing the sale, possession, and transportation of firearms, ammunition, and explosives in interstate commerce. Many of the ATF's activities are carried out in conjunction with task forces made up of state and local law enforcement officers, such as Project Safe Neighborhoods. The ATF operates a unique fire research laboratory in Beltsville, Maryland, where full-scale mock-ups of criminal arson can be reconstructed. The ATF had 5,285 employees and an annual budget of almost $1.5 billion in 2021. The ATF ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a power ratio of 101/10 (approximately ) or root-power ratio of 10 (approximately ). The unit expresses a relative change or an absolute value. In the latter case, the numeric value expresses the ratio of a value to a fixed reference value; when used in this way, the unit symbol is often suffixed with letter codes that indicate the reference value. For example, for the reference value of 1 volt, a common suffix is " V" (e.g., "20 dBV"). Two principal types of scaling of the decibel are in common use. When expressing a power ratio, it is defined as ten times the logarithm in base 10. That is, a change in ''power'' by a factor of 10 corresponds to a 10 dB change in level. When expressing root-power quantities, a change in ''ampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammer (firearm)
The hammer is a part of a firearm that is used to strike the percussion cap/primer, or a separate firing pin, to ignite the propellant and fire the projectile. It is so called due to the fact that it resembles a hammer in both form and function. The hammer itself is a metal piece that forcefully rotates about a pivot point. Evolution Firearms, initially known as "hand cannons", first became a viable weapon in 1364 through the advancement of chemical technologies to create a gunpowder efficient enough to launch a projectile at high speeds in a hand-held weapon. The issue quickly arose of how to effectively ignite the gunpowder while maintaining the weapon’s aim at the target. Initially, the problem was solved by using a "slow match": a chemically treated piece of rope that would stay lit for an extended period of time. The smoldering end of the rope would then be manually brought into contact with the gunpowder through a touch hole in the barrel of the weapon. when the user ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A-weighting
A-weighting is the most commonly used of a family of curves defined in the International standard IEC 61672:2003 and various national standards relating to the measurement of sound pressure level. A-weighting is applied to instrument-measured sound levels in an effort to account for the relative loudness perceived by the human ear, as the ear is less sensitive to low audio frequencies. It is employed by arithmetically adding a table of values, listed by octave or third-octave bands, to the measured sound pressure levels in dB. The resulting octave band measurements are usually added (logarithmic method) to provide a single A-weighted value describing the sound; the units are written as dB(A). Other weighting sets of values – B, C, D and now Z – are discussed below. The curves were originally defined for use at different average sound levels, but A-weighting, though originally intended only for the measurement of low-level sounds (around 40 phon), is now commonly used for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and even by industry. Further, both spellings are often used ''within'' a particular industry or country. Industries in British English-speaking countries typically use the "gauge" spelling. is the pressure relative to the ambient pressure. Various units are used to express pressure. Some of these derive from a unit of force divided by a unit of area; the SI unit of pressure, the pascal (Pa), for example, is one newton per square metre (N/m2); similarly, the pound-force per square inch (psi) is the traditional unit of pressure in the imperial and U.S. customary systems. Pressure may also be expressed in terms of standard atmospheric pressure; the atmosphere (atm) is equal to this pressure, and the torr is defined as of this. Manometric u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersonic
Supersonic speed is the speed of an object that exceeds the speed of sound ( Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times the speed of sound (Mach 5) are often referred to as hypersonic. Flights during which only some parts of the air surrounding an object, such as the ends of rotor blades, reach supersonic speeds are called transonic. This occurs typically somewhere between Mach 0.8 and Mach 1.2. Sounds are traveling vibrations in the form of pressure waves in an elastic medium. Objects move at supersonic speed when the objects move faster than the speed at which sound propagates through the medium. In gases, sound travels longitudinally at different speeds, mostly depending on the molecular mass and temperature of the gas, and pressure has little effect. Since air temperature and composition varies significantly with altitude, the speed of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propellant
A propellant (or propellent) is a mass that is expelled or expanded in such a way as to create a thrust or other motive force in accordance with Newton's third law of motion, and "propel" a vehicle, projectile, or fluid payload. In vehicles, the engine that expels the propellant is called a reaction engine. Although technically a propellant is the reaction mass used to create thrust, the term "propellant" is often used to describe a substance which is contains both the reaction mass and the fuel that holds the energy used to accelerate the reaction mass. For example, the term "propellant" is often used in chemical rocket design to describe a combined fuel/propellant, although the propellants should not be confused with the fuel that is used by an engine to produce the energy that expels the propellant. Even though the byproducts of substances used as fuel are also often used as a reaction mass to create the thrust, such as with a chemical rocket engine, propellant and fuel are two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Waves
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barrel (firearms)
A gun barrel is a crucial part of gun-type weapons such as small firearms, artillery pieces, and air guns. It is the straight shooting tube, usually made of rigid high-strength metal, through which a contained rapid expansion of high-pressure gas(es) is used to propel a projectile out of the front end ( muzzle) at a high velocity. The hollow interior of the barrel is called the bore, and the diameter of the bore is called its caliber, usually measured in inches or millimetres. The first firearms were made at a time when metallurgy was not advanced enough to cast tubes capable of withstanding the explosive forces of early cannons, so the pipe (often built from staves of metal) needed to be braced periodically along its length for structural reinforcement, producing an appearance somewhat reminiscent of storage barrels being stacked together, hence the English name.''A History of Warfare'' - Keegan, John, Vintage 1993. History Gun barrels are usually metal. However, the earl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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