Police Equipment
Revolvers : Revolver is a type of pistol equipped with a cylinder that consists of several chambers, which contains a cartridge or bullet. The cylinder revolves around an axis; each chamber in turn is brought into line between the firing mechanism and the barrel, which allows each bullet to pass through the barrel when the gun is fired. In some early revolvers of the 14th century, the cylinder consisted of several complete barrels.
In 1836, the American manufacturer Samuel Colt patented the Colt revolver. It had a single barrel and a small, revolving cylinder with six chambers. A similar revolver was developed at about the same time by the American gunsmith Edwin Wesson, but Colt won patent rights to the new pistol. The Colt revolver was loaded with a percussion cap, powder, and balls. The cylinder of the Colt was automatically turned when the hammer was drawn back for cocking, and the gun was then fired by pulling the trigger. In the 1850s the bullet replaced the percussion cap, powder, and ball. In 1873 the double-action revolver was developed. It makes possible to turn the cylinder, cock the hammer, and fire the gun with a single pull on the trigger. After 1900 the semi-automatic pistol is used in military. It reloads faster and had greater power.
History : Until the mid-1840s most pistols were single-shot muzzle-loaders fired by wheel lock, flintlock, and percussion ignition systems. In 1835 Samuel Colt patented the first percussion revolver. In the frame of this weapon, there was a revolving cylinder drilled with several chambers (usually five or six), into which powder and ball (or combustible paper cartridges containing powder and ball) were loaded from the front. In the rear of each chamber a percussion cap was placed over a hollow nipple. It directed the jet of flame to the powder when the cap was struck by the hammer. This type of revolver was eventually called ?cap-and-ball.? The earlier revolvers required the shooter to line up a chamber with the barrel and cock the hammer in separate steps. Colt devised a single-action mechanical linkage that rotated the cylinder as the hammer was cocked with the thumb. Colt dominated the manufacture of revolvers until the expiration of his US patent in 1857. At that time two Americans, Horace Smith and Daniel Wesson, produced the first cartridge revolver, based on a design purchased from Rollin White. Using rim-fire copper cartridges and eliminating the percussion-cap nipple, this weapon could be quickly loaded from the rear. When the Smith & Wesson patent expired in 1872, a host of new revolver designs appeared in the United States and Europe. The most important innovations were quick ejection of spent cartridges and the double-action cocking. By linking the trigger to the hammer-cocking and cylinder-revolving mechanisms, double action permitted a pistol to be fired with a simple pull of the trigger. This mechanism was first introduced on a cap-and-ball revolver, the English Beaumont-Adams of 1855, but it was quickly adapted to cartridge revolvers. There were several mechanisms for removing spent cartridge cases at that time. In the 1870s Smith & Wesson produced revolvers with hinged frames. When the barrel and cylinder of such a revolver were tipped on the hinge away from the hammer and handgrip?an ejector rod, located in the middle of the cylinder pushed out all the cartridges simultaneously. In the 1890s some Colt revolvers were made with solid frames. But it has cylinders that swung out to the side, where pushing an ejector rod forced out the cartridges. By the end of the 19th century the revolver had reached its definitive form and its highest possible effectiveness as a military weapon. Indeed, from the 1880s through World War II, British officers carried such revolvers as the .45-inch Webley and the .38-inch Enfield, both of which were the hinged-frame design. The U.S. military adopted various revolvers, usually of .38-inch or .45-inch calibre, until 1911, when it switched to auto-loading pistols.
Self-Loaders : A high rate of fire was especially crucial to last-ditch, close-quarters defense, and, with handguns as well as shoulder arms, this meant automatic loading. Following Hiram Maxim's experiments with self-loading weapons, automatic-pistol designs appeared in the last years of the 19th century. In 1893 Ludwig Loewe & Company introduced the first commercially viable self-loading pistol. Designed by an American, Hugo Borchardt, the 7.63-millimetre weapon operated on the principle of recoil. When the gun was fired, the barrel and breechblock, locked together by a ?toggle-link? mechanism, slid back together along the top of the frame. The toggle is essentially a two-piece arm hinged in the middle. It also recoiled for a short distance before it was forced to buckle upward at its hinge. This unlocked the breechblock from the barrel and allowed it to slide back on its own. It extracts and ejects the spent case, cocks the hammer, and compresses a coiled spring in the rear of the gun. The spring then pushed the breechblock forward, stripping a fresh cartridge from a magazine in the handgrip. It then toggle locked the breechblock once more against the barrel. Borchardt's toggle and spring mechanisms were improved by a German, Georg Luger, who came up with the 7.65-millimetre (later 9-millimetre) Parabellum pistol. This was adopted by the German army in 1908. In the United States and many parts of Europe, John Browning's handgun designs dominated the first half of the 20th century. In his .45-inch pistol, manufactured by Colt, the barrel and breechblock were covered and locked together by a housing called the slide. It was adapted by the US military. When the gun was fired, the recoiling slides pulled the barrel back a short distance until the barrel was disengaged and returned to its forward position by a spring. The unlocked slide and breechblock continued to move back, ejecting the spent case and cocking the hammer, until a spring forced them forward while a fresh cartridge was picked up from a seven-round magazine in the grip. The M1911 Colt remained until 1987. Its successor, the nine-millimetre Italian Beretta, given the NATO designation M9, reflected post-1970 trends such as large-capacity magazines (15 shots in the Beretta), double-action triggers (which could snap the hammer without its having to be cocked manually or automatically), and ambidextrous safety levers.
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