Revolver
A revolver (also called a wheel gun[1][2]) is a repeating handgun that has at least one barrel and uses a revolving cylinder containing multiple chambers (each holding a single cartridge) for firing. Because most revolver models hold up to six cartridges before needing to be reloaded, revolvers are also commonly called six shooters.
Before firing, cocking the revolver's hammer partially rotates the cylinder, indexing one of the cylinder chambers into alignment with the barrel, allowing the bullet to be fired through the bore. The hammer cocking in nearly all revolvers are manually driven, and can be achieved either by the user using the thumb to directly pull back the hammer (as in single-action), via internal linkage relaying the force of the trigger-pull (as in double-action), or both (as in double/single-action). By sequentially rotating through each chamber, the revolver allows the user to fire multiple times until having to reload the gun, unlike older single-shot firearms that had to be reloaded after each shot. Some rare revolver models can utilize the blowback of the preceding shot to automatically cock the hammer and index the next chamber, although these self-loading revolvers (known as automatic revolvers, despite technically being semi-automatic) never gained any widespread usage.
Although largely surpassed in convenience and ammunition capacity by semi-automatic pistols, revolvers still remain popular as back-up and off-duty handguns among American law enforcement officers and security guards and are still common in the American private sector as defensive, sporting, and hunting firearms. Famous revolvers models include the Colt 1851 Navy Revolver, the Webley, the Colt Single Action Army, the Colt Official Police, Smith & Wesson Model 10, the Smith & Wesson Model 29 of Dirty Harry fame, the Nagant M1895, and the Colt Python.
Though the majority of weapons using a revolver mechanism are handguns, other firearms may also have a revolver action. These include some models of rifles, shotguns, grenade launchers, and cannons. Revolver weapons differ from Gatling-style rotary weapons in that in a revolver only the chambers rotate, while in a rotary weapon there are multiple full firearm actions with their own barrels which rotate around a common ammunition feed.
In the development of firearms, an important limiting factor was the time required to reload the weapon after it was fired. While the user was reloading, the weapon was useless, allowing an adversary to attack the user. Several approaches to the problem of increasing the rate of fire were developed, the earliest involving multi-barrelled weapons which allowed two or more shots without reloading.[3] Later weapons featured multiple barrels revolving along a single axis.
A matchlock revolver with a single barrel and four chambers held at the Tower of London is believed to have been invented some time in the 15th century.[4] A revolving three-barrelled matchlock pistol in Venice is dated from at least 1548.[5] During the late 16th century in China, Zhao Shi-zhen invented the Xun Lei Chong, a five-barreled musket revolver spear. Around the same time, the earliest examples of what today is called a revolver were made in Germany. These weapons featured a single barrel with a revolving cylinder holding the powder and ball. They would soon be made by many European gun-makers, in numerous designs and configurations.[6]However, these weapons were complicated, difficult to use and prohibitively expensive to make, and as such they were not widely distributed.
