An extract on #sg2020
Most revolvers contain five or six rounds in the cylinder.
Though the original name was revolving gun/ wheel gun, the short-hand "revolver" is universally used. (Cannons using this mechanism are known as revolver cannon.) Nearly all early revolvers and many modern ones have six chambers in the cylinder, giving rise to the slang term six-shooter; however, revolvers with a number of different chambers have been made, with most modern revolvers having 5 or 6 chambers.
The revolver allows the user to fire multiple rounds without reloading after every shot, unlike older rifles and single shot firearms. Each time the user cocks the hammer, the cylinder revolves to align the next chamber and round with the hammer and barrel, which gives this type of firearm its name. In a single-action revolver, the user pulls the hammer back with their free hand or thumb. The trigger pull then releases the hammer, causing a functional and loaded gun to fire the bullet from the readied chamber. Because of the nature of this mechanism, the majority of revolvers are fully manual, requiring the user to cock the hammer before each shot, and then cocking it again for the next. This required action directly led to the development of the "quick shot" cocking technique associated with cowboys and the American Wild West, in which a shooter holds a revolver handgun steady in their dominant hand, while keeping their non-dominant hand poised just above the hammer while firing, allowing for much faster cocking than if the shooter was using both hands to steady the gun.
In a double-action revolver, pulling the trigger moves the hammer back, then releases it, which requires a longer and heavier trigger pull than single-action.
Loading and unloading most modern revolvers requires the operator to swing out the cylinder and manually insert additional ammunition directly into the chambers.
The first guns with multi-chambered cylinders that revolved to feed one barrel were made in the late 16th century in Europe. They were expensive and rare curiosities. Not until the 19th century would revolvers become common weapons of industrial production. One of the first was a flintlock revolver patented by Elisha Collier in 1814. The first percussion revolver was made by Lenormand of Paris in 1820 and the first percussion cap revolver was invented in Godoni, Italy by the Sardinian Francesco Antonio Broccu in 1833. He received a prize of 300 francs for his invention; although he did not patent it, his revolver was shown to King Charles Albert of Sardinia. However, in 1835 a similar handgun was patented by Samuel Colt, who would go on to make the first mass-produced revolver.
The first cartridge revolvers were produced around 1854 by Eugene Lefaucheux.
Revolvers soon became standard for nearly all uses. In the early 20th century, semi-automatic pistols were developed, which can hold more rounds, and are faster to reload. "Automatic" pistols also have a flat profile, more suitable for concealed carry. Semi-auto pistols were not considered reliable enough for serious police work or self-defense until the later half of the century, however, and revolvers were the dominant handgun for police and civilians until modern pistols such as the Beretta 92 and Glock 17 were developed in the 70s and 80s. Automatic pistols have almost completely replaced revolvers in military and law enforcement use (in military use, from 1910-1960; in law enforcement, in the 1980s and 1990s).
Revolvers still remain popular as back-up and off-duty handguns among American law enforcement officers and security guards. Also, revolvers are still common in the American private sector as defensive and sporting/hunting firearms. Famous police and military revolvers include the Webley, the Colt Single Action Army, the Colt Police Special, the Smith & Wesson Model 36, the Smith & Wesson Model 10, the Smith & Wesson 1917, the Smith & Wesson Model 3, and the Nagant M1895.