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.338 Xtreme
The ''.338 Xtreme cartridge'' (or .338 XT for short), is based on a necked down .505 Gibbs cartridge case with a sharper 35 degree shoulder angle. Introduced in 2008 by Xtreme Machining of Grassflat, Pa, the cases, commercially produced by Bertram Bullets, have a length of 3.030" and a head diameter of 0.640". Case capacity is 167.5 grains. Factory loads drive a 266 grain bullet at 3350 feet per second from a 30" barrel. The factory loads are loaded with a Tellurium Copper alloy solid very-low-drag bullet, These projectiles are manufactured by Xtreme Machining and of a patent pending design. The secant ogive projectile measures 1.808" long, including a 6 degree boat tail of 0.285". The patent refers to a "dual diameter" aspect of the projectile, where the main cylindrical portion of the bullet measures 0.331", 0.001" greater than the lands of the rifling. About 1.440" from the tip, the diameter increases to 0.338", creating a 0.15" " driving band". This both reduces driving for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xtreme Machining
Extreme may refer to: Science and mathematics Mathematics * Extreme point, a point in a convex set which does not lie in any open line segment joining two points in the set * Maxima and minima, extremes on a mathematical function Science * Extremophile, an organism which thrives in or requires "extreme" * Extremes on Earth *List of extrasolar planet extremes Politics * Extremism, political ideologies or actions deemed outside the acceptable range *The Extreme (Italy) or Historical Far Left, a left-wing parliamentary group in Italy 1867–1904 Business * Extreme Networks, a California-based networking hardware company * Extreme Records, an Australia-based record label * Extreme Associates, a California-based adult film studio Computer science *Xtreme Mod, a peer-to-peer file sharing client for Windows Sports and entertainment Sport * Extreme sport *Extreme Sports Channel A global sports and lifestyle brand dedicated to extreme sports and youth culture *Los Angeles Xtreme, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
505 Gibbs
The .505 Gibbs cartridge was designed by George Gibbs in 1911. The cartridge was originally known as the .505 Rimless Nitro Express. The C.I.P. refers to the cartridge as the 505 Mag. Gibbs in their publications. It is a .50 caliber (12.8 mm) rimless bottlenecked cartridge intended for magazine-fed rifles. General information The .505 Gibbs has a case capacity of of water. This cartridge was originally loaded with of cordite and bullet at for of kinetic energy. While the .505 Gibbs has a greater case capacity than most modern cartridges, it is loaded to lower pressures. The C.I.P. recommends a pressure of for the cartridge. As .505 Gibbs was intended for hunting dangerous game in tropical environments, and due to the temperature sensitivity of cordite, the lower pressures provide a greater safety and reliability margin. The .505 Gibbs has a unique bullet diameter of while most other .50 caliber bullets have diameters of . Barnes Bullets and Woodleigh Bullets are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bertram Bullet Company
Bertram may refer to: Places *Bertram, Western Australia, a suburb of Perth, Australia *Bertram, Iowa, United States, a city *Bertram, Texas, United States, a city *Bertram Building, a historic building in Austin, Texas *Bertram Glacier, Palmer Land, Antarctica Other uses *Bertram (name), a list of people and fictional characters with the given name or surname *Operation Bertram, an Allied deception operation leading up to the Second Battle of El Alamein *Bertram-class air-sea rescue boat, a Royal Australian Navy class of two vessels disposed of in 1988 *Bertram Hall (Radcliffe College), a dormitory building *Bertram Yacht, a subsidiary of the Ferretti Group See also *Bertrams, a UK book wholesaler *Bertrams, Gauteng Bertrams is a suburb of Johannesburg, South Africa. It is a small suburb found on the eastern edge of the Johannesburg central business district (CBD), tucked between the suburbs of New Doornfontein and Lorentzville, with Troyeville to the sou ..., a suburb of Jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tellurium Copper
Tellurium copper is an alloy of copper and tellurium. Tellurium improves the machinability of copper. Overview Tellurium is usually added to copper to improve machinability ("free cutting"). ASTM specification B301 has 0.5% tellurium; at concentrations of up to 0.75% machinability is improved while electrical conductivity and hot working behavior is maintained. Mechanical properties are similar to ''tough pitch copper'', while machinability is similar to brass - the hardness of the alloy is increased by precipitation of the copper telluride: weissite. Tellurium copper is not suited to welding, but it can be welded with gas shielded arc welding or resistance welding. It can be readily soft soldered, silver soldered, or brazed. Tellurium copper can be used as the electrode in electrical discharge machining (EDM) - the alloy is used to replace copper when grinding wheel Grinding wheels contains abrasive compounds for grinding and abrasive machining operations. Such wheels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very-low-drag Bullet
A very-low-drag bullet (VLD) is primarily a small arms ballistics development of the 1980s–1990s, driven by the design objective of bullets with higher degrees of accuracy and kinetic efficiency, especially at extended ranges. To achieve this, the projectile must minimize air resistance in flight. Usage has been greatest from military snipers and long-range target shooters, including F-class and benchrest competitors, but hunters have also benefited. Most VLD bullets are used in rifles. VLD bullets typically have a ballistic coefficient greater than 0.5, although the threshold is undefined. Bullets with a lower drag coefficient decelerate less rapidly. A low drag coefficient flattens the projectile's trajectory and also markedly decreases the lateral drift caused by crosswinds. The higher velocity of bullets with low drag coefficients means they retain more kinetic energy. Development VLD bullets are long and heavy for their diameter, to achieve a high sectional density. De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Driving Band
Russian 122 mm shrapnel shell, which has been fired, showing rifling marks on the copper driving band around its base and the steel bourrelet nearer the front A driving band or rotating band is a band of soft metal near the base of an artillery shell, often made of gilding metal, copper, or lead. When the shell is fired, the pressure of the propellant swages the metal into the rifling of the barrel and forms a seal; this seal prevents the gases from blowing past the shell, and engages the barrel's rifling to spin-stabilize the shell. Purpose The rotating band has three essential functions: * Center the rear end of the projectile in the gun barrel. * Seal the bore to prevent burning powder gas from moving through the rifling grooves past the projectile. * Engage with the rifling of the barrel to spin the projectile and stabilize its flight. Characteristics The shell is stabilized for yaw in the barrel by a smaller bourrelet band near the front of the projectile. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
338 Lapua Magnum
The .338 Lapua Magnum (8.6×70 mm or 8.58×70 mm) is a rimless, bottlenecked, centerfire rifle cartridge. It was developed during the 1980s as a high-powered, long-range cartridge for military snipers. It was used in the War in Afghanistan and the Iraq War. As a result of this, it has become widely available. The loaded .338 cartridge is in diameter (rim) and long. It can penetrate better-than-standard military body armor at ranges of up to , and has a maximum effective range of about with C.I.P. conforming ammunition at sea level conditions. Muzzle velocity is dependent on barrel length, seating depth, and powder charge, and varies from for commercial loads with bullets, which corresponds to about of muzzle energy. British military issue overpressure .338 Lapua Magnum cartridges with overall length, loaded with LockBase B408 very-low-drag bullets fired at 936 m/s (3,071 ft/s) muzzle velocity fired from a L115A3 Long Range Rifle were used in November 2009 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballistic Coefficient
In ballistics, the ballistic coefficient (BC, ''C'') of a body is a measure of its ability to overcome air resistance in flight. It is inversely proportional to the negative acceleration: a high number indicates a low negative acceleration—the drag on the body is small in proportion to its mass. BC can be expressed with the units kilograms per square meter (kg/m2) or pounds per square inch (lb/in2) (where 1 lb/in2 corresponds to ). Formulas General :C_\text = \frac = \frac where: *''C''b,Physics, ballistic coefficient as used in physics and engineering *''m'', mass *''A'', cross-sectional area *''C''d, drag coefficient *\rho, density *\ell, characteristic body length Ballistics The formula for calculating the ballistic coefficient for small and large arms projectiles ''only'' is as follows: :C_\text = \frac where: *''C''b,Projectile, ballistic coefficient as used in point mass trajectory from the Siacci method (less than 20 degrees). *''m'', mass of bullet *''d'', ... [...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] |
338 Lapua Magnum
The .338 Lapua Magnum (8.6×70 mm or 8.58×70 mm) is a rimless, bottlenecked, centerfire rifle cartridge. It was developed during the 1980s as a high-powered, long-range cartridge for military snipers. It was used in the War in Afghanistan and the Iraq War. As a result of this, it has become widely available. The loaded .338 cartridge is in diameter (rim) and long. It can penetrate better-than-standard military body armor at ranges of up to , and has a maximum effective range of about with C.I.P. conforming ammunition at sea level conditions. Muzzle velocity is dependent on barrel length, seating depth, and powder charge, and varies from for commercial loads with bullets, which corresponds to about of muzzle energy. British military issue overpressure .338 Lapua Magnum cartridges with overall length, loaded with LockBase B408 very-low-drag bullets fired at 936 m/s (3,071 ft/s) muzzle velocity fired from a L115A3 Long Range Rifle were used in November 2009 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
