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Fluting (firearms)
In firearms terminology, fluting refers to the removal of material from a cylindrical surface, usually creating grooves. This is most often the barrel of a rifle, though it may also refer to the cylinder of a revolver or the bolt of a bolt action rifle. In contrast to rifle barrels and revolver cylinders, rifle bolts are normally helically fluted, though helical fluting is sometimes also applied to rifle barrels. The main purpose of fluting is to reduce weight, and to a lesser extent increase rigidity for a given total weight or increase surface area to make the barrels less susceptible for overheating for a given total weight. However, for a given diameter, while a fluted barrel may cool more quickly, a non-fluted barrel will be stiffer and be able to absorb a larger amount of total heat at the price of additional total weight. In barrel chamber In the barrel chamber, fluting refers to gas relief flutes/grooves used to ease the extraction of cartridges. They may also come ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G22 Ohne Schalldaempfer
G, or g, is the seventh letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''gee'' (pronounced ), plural ''gees''. History The letter 'G' was introduced in the Old Latin period as a variant of ' C' to distinguish voiced from voiceless . The recorded originator of 'G' is freedman Spurius Carvilius Ruga, who added letter G to the teaching of the Roman alphabet during the 3rd century BC: he was the first Roman to open a fee-paying school, around 230 BCE. At this time, ' K' had fallen out of favor, and 'C', which had formerly represented both and before open vowels, had come to express in all environments. Ruga's positioning of 'G' shows that alphabetic order related to the letters' values as Greek numerals was a concern even in the 3rd century BC. According to some records, the original seventh letter, 'Z', had been purged from the Latin alphabet somewhat e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Shock
Thermal shock is a type of rapidly transient mechanical load. By definition, it is a mechanical load caused by a rapid change of temperature of a certain point. It can be also extended to the case of a thermal gradient, which makes different parts of an object expand by different amounts. This differential expansion can be more directly understood in terms of strain, than in terms of stress, as it is shown in the following. At some point, this stress can exceed the tensile strength of the material, causing a crack to form. If nothing stops this crack from propagating through the material, it will cause the object's structure to fail. Failure due to thermal shock can be prevented by: # Reducing the thermal gradient seen by the object, by changing its temperature more slowly or increasing the material's thermal conductivity # Reducing the material's coefficient of thermal expansion # Increasing its strength # Introducing built-in compressive stress, as for example in tempe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squeeze Bore
A squeeze bore, alternatively taper-bore, cone barrel or conical barrel, is a weapon where the internal barrel diameter progressively decreases towards the muzzle resulting in a reduced final internal diameter. These weapons are used in conjunction with special sub-caliber ammunition where the projectile is fitted with soft-metal flanges which fills out the caliber. As the projectile travels through the squeeze bore the flanges fold inwards, resulting in a reduced caliber round with an increased velocity compared to a traditional full-caliber round. Mechanism A squeeze bore utilizes the energy of the propellant to squeeze the diameter of the bullet or shell down, increasing penetration and velocity significantly. This process also meant high chamber pressure and low barrel service life. For example, the service life of a squeeze bore 7.5 cm Pak 41 could be as low as 1000 rounds compared to 5000-7000 rounds for the 7.5 cm Pak 39 (L/48). The diameter of a fired shell could dec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
StG 45(M)
The StG 45(M) (abbreviation of Sturmgewehr 45, "Assault Rifle 45") sometimes referred to as the MP 45(M), was a prototype assault rifle developed by Mauser for the ''Wehrmacht'' at the end of World War II, using an innovative roller-delayed blowback operating system. It fired the 7.92×33mm Kurz (or "Pistolenpatrone 7.9mm") intermediate cartridge at a cyclic rate of around 450 rounds per minute. Overview The origin of this rifle can be traced back to the final years of World War II when Mauser engineers at the Light Weapon Development Group (''Abteilung 37'') at Oberndorf am Neckar designed the MKb ''Gerät'' 06 (''Maschinenkarabiner Gerät 06'' or "machine carbine instrument 06") prototype assault rifle chambered for the intermediate 7.92×33mm Kurz cartridge, first with the ''Gerät'' 06 model using a roller-locked mechanism which was unique for being gas operated, as opposed to recoil operation, originally adapted from the MG 42 machine gun, but with a fixed barrel and co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AA-52 Machine Gun
The ''AA-52'' (full designation in French: ''Arme Automatique Transformable Modèle 1952'', "Transformable automatic weapon model 1952") is one of the first French-produced guns of the post–World War II era. It was manufactured by the French government-owned Manufacture d'armes de Saint-Étienne (MAS) company. The AA-52 is still used today as a vehicle-mounted weapon due to large quantities in service, but has been replaced in the helicopter role by the Belgian FN MAG, starting with the EC 725 Caracal of the special operations units and the Air Force search and rescue teams. The AA-52 had been largely phased out for infantry use in favour of the lighter FN Minimi but remains in use. History The AA-52 general-purpose machine gun was conceived and developed following the French military's experiences in the First Indochina War during the early 1950s. At that time, the French army was equipped with an assortment of weapons from British and American sources, as well as some Germ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FAMAS
The FAMAS (''Fusil d'Assaut de la Manufacture d'Armes de Saint-Étienne'', "Assault Rifle from the Saint-Étienne Weapon Factory") is a bullpup assault rifle designed and manufactured in France by MAS in 1978, a year after the Austrian Steyr AUG. It is known by French troops as ''Le Clairon'' (The Bugle) due to its distinctive shape. The FAMAS is recognised for its high rate of fire at 1,100 rounds per minute. Beginning in 2017, the FAMAS was replaced in most frontline units in the French Army by the HK416F, and the FAMAS is expected to remain in limited service until 2028. History The first French bullpup rifles were developed between 1946 and 1950 at the AME (''Atelier Mécanique de Mulhouse'') and MAS, testing rounds such as .30 US Carbine, 7.92×33mm Kurz, 7.65×38mm (Made by ''Cartoucherie de Valence'') and some other intermediate calibers. Since France was engaged in the First Indochina War at the time, and was also the second-largest contributor to NATO, the resea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heckler & Koch G3
The Heckler & Koch G3 (''Gewehr'' 3) is a 7.62×51mm NATO, select-fire battle rifle developed in the 1950s by the German armament manufacturer Heckler & Koch (H&K) in collaboration with the Spanish state-owned design and development agency CETME (''Centro de Estudios Técnicos de Materiales Especiales''). The modular designed G3 has over the years been exported to over 70 countries and manufactured under licence in at least 15 countries, bringing the total number built to around 7,800,000. The G3 was the service rifle of the armed forces of Germany until it was replaced by the G36 in the 1990s. History The origin of the G3 can be traced back to the final years of World War II when Mauser engineers at the Light Weapon Development Group (''Abteilung 37'') at Oberndorf am Neckar designed the ''Maschinenkarabiner Gerät 06'' (MKb ''Gerät'' 06, "machine carbine device 06") prototype assault rifle chambered for the intermediate 7.92×33mm ''Kurz'' cartridge, first with the '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blowback (firearms)
Blowback is a system of operation for self-loading firearms that obtains energy from the motion of the cartridge case as it is pushed to the rear by expanding gas created by the ignition of the propellant charge. Several blowback systems exist within this broad principle of operation, each distinguished by the methods used to control bolt movement. In most actions that use blowback operation, the breech is not locked mechanically at the time of firing: the inertia of the bolt and recoil , relative to the weight of the bullet, delay opening of the breech until the bullet has left the barrel. A few locked breech designs use a form of blowback (example: primer actuation) to perform the unlocking function. The blowback principle may be considered a simplified form of gas operation, since the cartridge case behaves like a piston driven by the powder gases. Other operating principles for self-loading firearms include delayed blowback, blow forward, gas operation, and recoil operat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chamber (firearms)
In firearms, the chamber is the cavity at the back end of a breechloader's barrel or cylinder, where the cartridge is inserted before being fired. The rear opening of the chamber is the breech, and is sealed by the breechblock or the bolt. Function Rifles and pistols generally have a single chamber integral to their barrels, but revolvers have multiple chambers in their cylinder, and no chamber in their barrel. Thus, rifles and pistols can usually still be fired with the magazine removed as long as a cartridge is inserted into the chamber, while a revolver cannot be fired at all with its cylinder swung out. The act of ''chambering'' a cartridge means the insertion of a round into the chamber, either manually or through the action of the weapon, e.g., pump-action, lever-action, bolt action, or Autoloading operation generally in anticipation of firing the weapon, without need to "load" the weapon upon decision to use it (reducing the number of ''actions'' needed to d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DCB Shooting G3 Roller System3
DCB may stand for: * Dame Commander of the Order of the Bath * Development Credit Bank, a private-sector bank in India * David Campbell Bannerman (born 1960), a British politician * David Crowder Band, a Christian rock band * ''Dictionary of Canadian Biography'' * Dead cat bounce, a figurative term used by traders in the finance industry * Dulwich College Beijing, a British international school in Beijing, China In science and technology * Disconnecting circuit breaker, a high-voltage circuit breaker with disconnectors integrated into the breaking chamber * Data center bridging, in computer networking * Data Control Block, a data structure for accessing data sets on IBM mainframes * Double Cantilever Beam, a test specimen in fracture mechanics * Dichlorobenzene * Digital Control Bus, a proprietary MIDI-like interface by Roland Corporation * Direct Copper Bonding, also Direct Bonding Copper, a type of power electronic substrate * Direct Carrier Billing, a method of doing digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for the diameter of a sphere. In more modern usage, the length d of a diameter is also called the diameter. In this sense one speaks of diameter rather than diameter (which refers to the line segment itself), because all diameters of a circle or sphere have the same length, this being twice the radius r. :d = 2r \qquad\text\qquad r = \frac. For a convex shape in the plane, the diameter is defined to be the largest distance that can be formed between two opposite parallel lines tangent to its boundary, and the is often defined to be the smallest such distance. Both quantities can be calculated efficiently using rotating calipers. For a curve of constant width such as the Reuleaux triangle, the width and diameter are the same because a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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