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Calibers
In guns, particularly firearms, caliber (or calibre; sometimes abbreviated as "cal") is the specified nominal internal diameter of the gun barrel bore – regardless of how or where the bore is measured and whether the finished bore matches that specification. It is measured in inches or in millimeters. In the United States it is expressed in hundredths of an inch; in the United Kingdom in thousandths; and elsewhere in millimeters. For example, a "45 caliber" firearm has a barrel diameter of roughly . Barrel diameters can also be expressed using metric dimensions. For example, a "9 mm pistol" has a barrel diameter of about 9 millimeters. Since metric and US customary units do not convert evenly at this scale, metric conversions of caliber measured in decimal inches are typically approximations of the precise specifications in non-metric units, and vice versa. In a rifled barrel, the distance is measured between opposing lands or between opposing grooves; groove measu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifling
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the projectile longitudinally by conservation of angular momentum, improving its aerodynamic stability and accuracy over smoothbore designs. Rifling is characterized by its twist rate, which indicates the distance the rifling takes to complete one full revolution, such as "1 turn in 10 inches" (1:10 inches), "1 turn in 254 mm" ("1:254 mm" or "1:25.4 cm)", or the like. Normally, an experienced shooter can infer the units of measurement from the numbers alone. A shorter distance indicates a faster twist, meaning that for a given velocity the projectile will rotate at a higher spin rate. The combination of length, weight, and shape of a projectile determines the twist rate needed to gyroscopically stabilize it – barr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifling
In firearms, rifling is machining helical grooves into the internal (bore) surface of a gun's barrel for the purpose of exerting torque and thus imparting a spin to a projectile around its longitudinal axis during shooting to stabilize the projectile longitudinally by conservation of angular momentum, improving its aerodynamic stability and accuracy over smoothbore designs. Rifling is characterized by its twist rate, which indicates the distance the rifling takes to complete one full revolution, such as "1 turn in 10 inches" (1:10 inches), "1 turn in 254 mm" ("1:254 mm" or "1:25.4 cm)", or the like. Normally, an experienced shooter can infer the units of measurement from the numbers alone. A shorter distance indicates a faster twist, meaning that for a given velocity the projectile will rotate at a higher spin rate. The combination of length, weight, and shape of a projectile determines the twist rate needed to gyroscopically stabilize it &ndash ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifle Cartridge Comparison
A rifle is a long-barreled firearm designed for accurate shooting, with a barrel that has a helical pattern of grooves (rifling) cut into the bore wall. In keeping with their focus on accuracy, rifles are typically designed to be held with both hands and braced firmly against the shooter's shoulder via a buttstock for stability during shooting. Rifles are used extensively in warfare, law enforcement, hunting, shooting sports, and crime. The term was originally ''rifled gun'', with the verb ''rifle'' referring to the early modern machining process of creating groovings with cutting tools. By the 20th century, the weapon had become so common that the modern noun ''rifle'' is now often used for any long-shaped handheld ranged weapon designed for well-aimed discharge activated by a trigger (e.g., personnel halting and stimulation response rifle, which is actually a laser dazzler). Like all typical firearms, a rifle's projectile (bullet) is propelled by the contained def ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Small-bore
Small-bore refers to calibers with a diameter of .32 inches or smaller. It may also refer to small-bore rifle competition. The medium-bore refers to calibers with a diameter between .33 inches up to .39 inches and large-bore refers to calibers with a diameter of .40 inches or larger. Miniature bore historically referred to calibers of .22 inches or smaller. There is much variance in the use of the term small-bore which over the years has changed considerably with anything under .577 caliber considered small-bore prior to the mid-19th century. __NOTOC__ Small-bore competition Small-bore competition often refers to shooting competitions conducted with .22 Rimfire target rifles.http://compete.nra.org/documents/pdf/compete/RuleBooks/SBR/sbr-book.pdf Small-bore rifle NRA rule book See also * List of rifle cartridges * Table of handgun and rifle cartridges This is a table of selected pistol/ submachine gun and rifle/ machine gun cartridges by common name. Data values are the highest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rimfire Ammunition
Rimfire ammunition is a type of firearm metallic cartridge whose primer is located within a hollow circumferential rim protruding from the base of its casing. When fired, the gun's firing pin will strike and crush the rim against the edge of the barrel breech, sparking the primer compound within the rim, and in turn ignite the propellant within the case. Invented in 1845, by Louis-Nicolas Flobert, the first rimfire metallic cartridge was the .22 BB Cap (a.k.a. 6mm Flobert) cartridge, which consisted of a percussion cap with a bullet attached to the top. While many other different cartridge priming methods have been tried since the 19th century, only rimfire and the later centerfire cartridges survive to the present day with regular usages. The .22 Long Rifle rimfire cartridge, introduced in 1887, is by far the most common ammunition in the world today in terms of units sold. Characteristics Rimfire ammunition is so named because the firing pin strikes and crushes the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firearm
A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears to make the portable fire lance, operable by a single person, which was later used effectively as a shock weapon in the Siege of De'an in 1132. In the 13th century, fire lance barrels were replaced with metal tubes and transformed into the metal-barreled hand cannon. The technology gradually spread throughout Eurasia during the 14th century. Older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other propellants. Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart spin to the projectile for improved flight stability. Modern firearms can be described by their caliber ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
45-70
The .45-70 rifle cartridge, also known as the .45-70 Government, was developed at the U.S. Army's Springfield Armory for use in the Springfield Model 1873, which is known to collectors as the "Trapdoor Springfield." The new cartridge was a replacement for the stop-gap .50-70 Government cartridge, which had been adopted in 1866, one year after the end of the American Civil War. Nomenclature The new cartridge was completely identified as the ''.45-70-405'', but was also referred to as the ".45 Government" cartridge in commercial catalogs. The nomenclature of the time was based on three properties of the cartridge: * .45: nominal diameter of bullet, measured in decimal inches, i.e., 0.458 inches (11.63 mm); * 70: weight of black powder, measured in grains, i.e., 70 grains (4.56 g); * 405: weight of lead bullet, measured in grains, i.e., 405 grains (26.38 g). The minimum acceptable accuracy of the .45-70 from the 1873 Springfield was approximately at , however, the heavy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gauge (firearms)
The gauge (or commonly bore in British English) of a firearm is a unit of measurement used to express the inner diameter (bore diameter) of the barrel. Gauge is determined from the weight of a solid sphere of lead that will fit the bore of the firearm and is expressed as the multiplicative inverse of the sphere's weight as a fraction of a pound, e.g., a one-twelfth pound lead ball fits a 12-gauge bore. Thus there are twelve 12-gauge balls per pound, etc. The term is related to the measurement of cannon, which were also measured by the weight of their iron round shot; an 8-pounder would fire an 8 lb (3.6 kg) ball. Gauge is commonly used today in reference to shotguns, though historically it was also used in large double rifles, which were made in sizes up to 2 bore during their heyday in the 1880s, being originally loaded with black powder cartridges. These very large rifles, called " elephant guns", were intended for use primarily in Africa and Asia for hunting large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cartridge (firearms)
A cartridge or a round is a type of pre-assembled firearm ammunition packaging a projectile (bullet, shot, or slug), a propellant substance (usually either smokeless powder 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 the practical purpose of convenient transportation and handling during shooting. Although in popular usage the term "bullet" is often informally used to refer to a complete cartridge, it is correctly used only to refer to the projectile. Cartridges can be categorized by the type of their primers – a small charge of an impact- or electric-sensitive chemical mixture that is located: at the center of the case head ( centerfire); inside the rim ( rimfire); inside the walls on the fold of the case base that is shaped like a cup (cupfire, now obsolete); in a sideways projection that is shaped like a pin ( pinfire, now obsolete); ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Powder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate ( saltpeter). The sulfur and carbon act as fuels while the saltpeter is an oxidizer. Gunpowder has been widely used as a propellant in firearms, artillery, rocketry, and pyrotechnics, including use as a blasting agent for explosives in quarrying, mining, building pipelines and road building. Gunpowder is classified as a low explosive because of its relatively slow decomposition rate and consequently low brisance. Low explosives deflagrate (i.e., burn at subsonic speeds), whereas high explosives detonate, producing a supersonic shockwave. Ignition of gunpowder packed behind a projectile generates enough pressure to force the shot from the muzzle at high speed, but usually not enough force to rupture the gun barrel. It thus makes a good prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wildcat Cartridge
A wildcat cartridge, often shortened to wildcat, is a custom cartridge for which ammunition and/or firearms are not mass-produced. These cartridges are often created in order to optimize a certain performance characteristic (such as the power, size, or efficiency) of an existing commercial cartridge. Developing and using wildcat cartridges does not generally serve a purpose in military or law enforcement; it is more a hobby for serious shooting, hunting, gunsmithing, and handloading enthusiasts, particularly in the United States. There are potentially endless varieties of wildcat cartridge: one source of gunsmithing equipment has a library of over 6,000 different wildcat cartridges for which they produce equipment such as chamber reamers. Development of a wildcat Often, wildcats are commercially sold rounds that have been modified in some way to alter the cartridge's performance. Barrels for the caliber are originally manufactured by gunsmiths specializing in barrel making. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
