1.
United States
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Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography, climate and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations. In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
2.
Smith & Wesson
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Smith & Wesson is a manufacturer of firearms in the United States. The corporate headquarters are based in Springfield, Massachusetts, founded in 1852, Smith & Wessons pistols and revolvers have become standard issue to police and armed forces throughout the world, in addition to their popularity among sport shooters. Apart from firearms, Smith & Wesson has been known for the types of ammunition it has introduced over the years. Wesson founded the Smith & Wesson Company in Norwich, Connecticut in 1852 to develop the Volcanic rifle, Smith developed a new Volcanic Cartridge, which he patented in 1854. The Smith & Wesson Company was renamed Volcanic Repeating Arms in 1855, Smith left the company and returned to his native Springfield, Massachusetts, Wesson stayed on as plant manager with Volcanic Repeating Arms. As Samuel Colts patent on the revolver was set to expire in 1856 and his research pointed out that a former Colt employee named Rollin White held the patent for a Bored-through cylinder, a component he would need for his invention. Wesson reconnected with Smith and the two partners approached White to manufacture a newly designed revolver-and-cartridge combination, rather than make White a partner in their company, Smith and Wesson paid him a royalty of $0.25 on every revolver that they made. It would become Whites responsibility to defend his patent in any court cases which led to his financial ruin. The orders for the Smith & Wesson Model 1 revolver outpaced the production capabilities. In 1860 demand was so great that Smith & Wesson expanded into a new facility, at the same time, the companys design was being infringed upon by other manufacturers which led to numerous lawsuits filed by Rollin White. In many of these part of the restitution came in the form of the offender being forced to stamp Manufactured for Smith & Wesson on the revolvers in question. Whites vigorous defense of his patent caused a problem for armsmakers in the United States at the time as they could not manufacture cartridge revolvers, at the end of the war the US Government charged White with causing the retardation of arms development in America. Demand for revolvers declined at the close of the Civil War, in 1870 the company introduced a large frame revolver in heavier calibers than the pocket sized revolvers it had been making. The design was known as the Smith & Wesson Model 3, after an organized campaign by the NRA and NSSF, thousands of retailers and tens of thousands of firearms consumers boycotted Smith & Wesson. On 11 May 2001, Saf-T-Hammer Corporation acquired Smith & Wesson Corp. from Tomkins plc for US$15 million, Saf-T-Hammer assumed US$30 million in debt, bringing the total purchase price to US$45 million. The acquisition of Smith & Wesson was chiefly brokered by Saf-T-Hammer President Bob Scott, after the purchase, Scott became the president of Smith & Wesson to guide the 157-year-old company back to its former standing in the market. On 15 February 2002, the name of the newly formed entity was changed to Smith & Wesson Holding Corporation, about 2006 Smith & Wesson refocused its marketing on big box retailers, according to Smith & Wesson CEO Mike Golden in a 2008 conference call with investors. In December 2014, Smith & Wesson Holding announced it was paying $130.5 million for Battenfeld Technologies, the company made the acquisition with the eventual intent to merge all its existing Smith & Wesson, M&P and Thompson Center Arms accessories into a single division
3.
Rifling
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In firearms, rifling consists of helical grooves in the internal surface of a guns barrel, which impart a spin to a projectile around its long axis. This spin serves to stabilize the projectile, improving its aerodynamic stability. Rifling is often described by its twist rate, which indicates the distance the rifling takes to complete one revolution, such as 1 turn in 10 inches. A shorter distance indicates a faster twist, meaning that for a given velocity the projectile will be rotating at a spin rate. Barrels intended for long, small-diameter bullets, such as the ultra-low-drag, 80-grain 0.223 inch bullets, extremely long projectiles such as flechettes may require high twist rates, these projectiles must be inherently stable, and are often fired from a smoothbore barrel. Muskets were smoothbore, large caliber weapons using ball-shaped ammunition fired at low velocity. Due to the high cost and great difficulty of manufacturing, and the need to load readily from the muzzle. Consequently, on firing the ball bounced off the sides of the barrel when fired, barrel rifling was invented in Augsburg, Germany in 1498. In 1520 August Kotter, an armourer of Nuremberg, Germany improved upon this work, though true rifling dates from the mid-16th century, it did not become commonplace until the nineteenth century. The most successful weapons using rifling with black powder were breech loaders such as the Queen Anne pistol, the grooves most commonly used in modern rifling have fairly sharp edges. More recently, polygonal rifling, a throwback to the earliest types of rifling, has become popular, polygonal barrels tend to have longer service lives because the reduction of the sharp edges of the land reduces erosion of the barrel. Supporters of polygonal rifling also claim higher velocities and greater accuracy, polygonal rifling is currently seen on pistols from CZ, Heckler & Koch, Glock, Tanfoglio, and Kahr Arms, as well as the Desert Eagle. Such guns have achieved significant increases in velocity and range. Examples include the South African G5 and the German PzH2000, gain-twist rifling begins with very little change in the projectiles angular momentum during the first few inches of bullet travel after ignition during the transition from chamber to throat. This enables the bullet to remain undisturbed and trued to the case mouth. After engaging the rifling the bullet is progressively subjected to accelerated angular momentum as burning powder propels it down the barrel. By only gradually increasing the rate, torque is spread along a much longer section of barrel. Gain-twist rifling was used as early as the American Civil War, colt Army and Navy revolvers both employed gain-twist rifling
4.
Smokeless powder
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Smokeless powder is the name given to a number of propellants used in firearms and artillery that produce negligible smoke when fired, unlike the black powder they replaced. The basis of the term smokeless is that the products are mainly gaseous. Despite its name, smokeless powder is not completely free of smoke, while there may be little noticeable smoke from small-arms ammunition, since the 14th century gunpowder was not actually a physical powder, and smokeless powder can be produced only as a pelletized or extruded granular material. Smokeless powder allowed the development of modern semi- and fully automatic firearms and lighter breeches, burnt black powder leaves a thick, heavy fouling that is hygroscopic and causes rusting of the barrel. The fouling left by smokeless powder exhibits none of these properties and this makes an autoloading firearm with many moving parts feasible. However, they are used as propellants, in normal use. Before the widespread introduction of smokeless powder the use of black powder caused many problems on the battlefield, Military commanders since the Napoleonic Wars reported difficulty with giving orders on a battlefield obscured by the smoke of firing. Verbal commands could not be heard above the noise of the guns, unless there was a strong wind, after a few shots, soldiers using black powder ammunition would have their view obscured by a huge cloud of smoke. Snipers or other concealed shooters were given away by a cloud of smoke over the firing position, black powder is also corrosive, making cleaning mandatory after every use. Likewise, black powders tendency to produce severe fouling caused actions to jam, nitroglycerine was synthesized by the Italian chemist Ascanio Sobrero in 1847. Nitroglycerine is also sensitive, making it unfit to be carried in battlefield conditions. A major step forward was the discovery of guncotton, a nitrocellulose-based material and he promoted its use as a blasting explosive and sold manufacturing rights to the Austrian Empire. Guncotton was more powerful than gunpowder, but at the time was once again somewhat more unstable. John Taylor obtained an English patent for guncotton, and John Hall & Sons began manufacture in Faversham, English interest languished after an explosion destroyed the Faversham factory in 1847. Small arms could not withstand the pressures generated by guncotton, Abel patented this process in 1865 when the second Austrian guncotton factory exploded. After the Stowmarket factory exploded in 1871, Waltham Abbey began production of guncotton for torpedo, in 1863, Prussian artillery captain Johann F. E. Schultze patented a small-arms propellent of nitrated hardwood impregnated with saltpeter or barium nitrate. Prentice received an 1866 patent for a powder of nitrated paper manufactured at Stowmarket. In 1871, Frederick Volkmann received an Austrian patent for a version of Schultze powder called Collodin
5.
Centerfire ammunition
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A centerfire cartridge is a cartridge with a primer located in the center of the cartridge case head. Unlike rimfire cartridges, the primer is a separate and replaceable component, centerfire cartridges have supplanted the rimfire variety in all but the smallest cartridge sizes. The stronger base of a cartridge is able to withstand higher pressures which in turn give a bullet greater velocity. Larger caliber rimfire cartridges require greater volumes of priming explosive than centerfire cartridges, reducing the amount of priming explosive would reduce the reliability of rimfire cartridge ignition, and increase the probability of misfire or dud cartridges. Economies of scale are achieved through interchangeable primers for a variety of centerfire cartridge calibers. The expensive individual brass cases can be reused after replacing the primer, gunpowder, the forward portion of some empty cases can be reformed for use as obsolete or wildcat cartridges with similar base configuration. Modern cartridges larger than.22 caliber are mostly centerfire, actions suitable for larger caliber rimfire cartridges declined in popularity until the demand for them no longer exceeded manufacturing costs, and they became obsolete. An early form of ammunition, without a percussion cap, was invented between 1808 and 1812 by Jean Samuel Pauly. This was also the first fully integrated cartridge, true centerfire ammunition was invented by the Frenchman Clement Pottet in 1829. However, Pottet would not perfect his design until 1855, the centerfire cartridge was improved by Benjamin Houllier, Gastinne Renette, Charles Lancaster, George Morse, Francois Schneider, Hiram Berdan and Edward Mounier Boxer. The identifying feature of centerfire ammunition is the primer which is a cup containing a primary explosive inserted into a recess in the center of the base of the cartridge. The firearm firing pin crushes this explosive between the cup and an anvil to produce hot gas and a shower of incandescent particles to ignite the powder charge, Berdan priming is less expensive to manufacture and is much more common in military-surplus ammunition made outside the United States. Berdan primers are named after their American inventor, Hiram Berdan of New York who invented his first variation of the Berdan primer and patented it on March 20,1866, in U. S. A small copper cylinder formed the shell of the cartridge, and this system worked well, allowing the option of installing a cap just before use of the propellant-loaded cartridge as well as permitting reloading the cartridge for reuse. S. Berdan primers have remained essentially the same functionally to the present day, Berdan primers are similar to the caps used in the caplock system, being small metal cups with pressure-sensitive explosive in them. Modern Berdan primers are pressed into the pocket of a Berdan-type cartridge case. Inside the primer pocket is a bump, the anvil, that rests against the center of the cup. Berdan cases are reusable, although the process is rather involved, the used primer must be removed, usually by hydraulic pressure or a pincer or lever that pulls the primer out of the bottom
6.
Gunpowder
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Gunpowder, also known as black powder, is the earliest known chemical explosive. It is a mixture of sulfur, charcoal, and potassium nitrate, the sulfur and charcoal act as fuels, and the saltpeter is an oxidizer. Black powder firearms are in limited use today in hunting, shooting, Black powder has been replaced for most industrial uses by high explosives such as dynamite. Black powder is assigned the UN number UN0027 and has a class of 1. 1D. It has a point of approximately 427–464 °C. The specific flash point may vary based on the composition of the gunpowder. Gunpowders specific gravity is 1. 70–1.82 or 1. 92–2.08, Gunpowder is classified as a low explosive because of its relatively slow decomposition rate and consequently low brisance. Low explosives deflagrate at subsonic speeds, whereas high explosives detonate, ignition of the powder packed behind a bullet must generate enough pressure to force it from the muzzle at high speed, but not enough to rupture the gun barrel. Gunpowder thus makes a good propellant, but is suitable for shattering rock or fortifications. Gunpowder was widely used to fill artillery shells and in mining and civil engineering to blast rock until the half of the 19th century. Black powder is used as a delay element in various munitions where its slow-burning properties are valuable. The spread of gunpowder across Asia from China is widely attributed to the Mongols, the earliest record of a written formula for gunpowder appears in the 11th century Song dynasty text, Wujing Zongyao. This discovery led to the invention of fireworks and the earliest gunpowder weapons in China, in the centuries following the Chinese discovery, gunpowder weapons began appearing in the Muslim world and Europe. The technology spread from China through the Middle East or Central Asia, the earliest Western accounts of gunpowder appear in texts written by English philosopher Roger Bacon in the 13th century. The most ardent protagonists were Nathaniel Halhad, Johann Backmann, Quintin Craufurd, however, due to lack of sufficient proof, these theories have not been widely accepted. A major problem confronting the study of the history of gunpowder is ready access to sources close to the events described. The translation difficulty has led to errors or loose interpretations bordering on artistic licence, early writings potentially mentioning gunpowder are sometimes marked by a linguistic process where old words acquired new meanings. For instance, the Arabic word naft transitioned from denoting naphtha to denoting gunpowder, saltpeter was known to the Chinese by the mid-1st century AD and there is strong evidence of the use of saltpeter and sulfur in various largely medicinal combinations
