History of the revolver
Attempts to create a weapon with a single barrel and a revolving cylinder containing the charges were made since the 16th century. The first fully functional design, however, was patented only in 1836 by Samuel Colt in the USA. Colt's revolver used a mechanically indexing cylinder which, according to Samuel Colt himself, was inspired by a nautical capstan, which had a ratchet and pawl mechanism. This design influenced all subsequent revolver mechanisms.
Design: how a revolver works
In modern revolvers there are several firing chambers (usually five or six, but sometimes more depending on gun caliber and model) arranged in a circle in a cylinder. A spring-loaded hammer is positioned on the other side of the cylinder, in line with the barrel. The chambers are aligned one at a time with the barrel thanks to a ratchet-and-pawl rotating mechanism connected to the hammer and trigger. Cartridges are inserted in each chamber. When the trigger is pulled, the hammer strikes the cartridge primer that ignites the propelling charge: since the chamber is in line with the barrel, the bullet is pushed through it exiting the cylinder.
More information about types of revolvers you'll find at the end of the page.
Single action revolver versus double action revolver
In a single-action revolver the hammer must be pulled back (cocked) by hand before each shot, which also revolves the cylinder. In a double action revolver, the hammer can be still be pulled back by hand but the shooter can also cock it and shoot by just squeezing the trigger in one longer motion.
In both cases, after each shot the mechanism will revolve the cylinder aligning a new loaded chamber with the barrel. That's a traditional double-action or, more correctly, a single-double - or “mixed” - action: there exist revolvers that can't be cocked by hand and are “double action only”. Shooting in single action the force and distance required to pull the trigger can be minimal, while operating in double-action requires a longer trigger squeeze (the mechanism must force the hammer backwards and revolve the cylinder). Double action revolvers can be fired faster than a single-action - you don't have to cock the hammer after each shot - but accuracy may be reduced since trigger-pull is heavier and longer.
Revolver vs. pistol: what's better?
Having no external levers and controls apart from trigger, hammer and cylinder release, revolvers are generally simpler to operate and theoretically more reliable than semi-automatic pistols. In case of misfire, with a revolver you have just to pull the trigger again: the cylinder will rotate and align a new cartridge with the barrel. With a semi-auto you will have to clean the chamber operating the slide to remove the misfired round. Revolver grips also doesn't hold a magazine, so they are usually more ergonomic and smaller, which is good for concealed carry and customization. Lastly, revolvers can be kept loaded and ready to fire without the need to manipulate any safety system.
On the other hand, the internal mechanism of revolvers is more complex and delicate. Revolvers can hold fewer rounds than an average semi-automatic pistol of the same size too - the latter can hold from 7 to 15 cartridges or more in its magazine. Finally, revolvers are slower to reload.
Revolver: loading and unloading
In old front-loading revolvers and their modern replicas each chamber had to be loaded from the cylinder front with loose powder and bullet, which had to be rammed in place. Firing caps were then placed on the nipples on the rear face of the cylinder. After the advent of metallic cartridges, later revolver models had a loading gate at the rear of the cylinder that allowed insertion of one cartridge at a time for loading. Before reloading, each fired case had to be ejected operating a rod under the barrel.
It was still a time consuming operation. The next step in design was the top-break revolver, with the frame hinged at the bottom front of the cylinder so that releasing the lock and pushing the barrel down the rear face of the cylinder could be exposed for reloading. In the “tip-up” variant, the barrel pivoted upwards and in most models spent case were automatically ejected.
Modern revolvers have a swing-out cylinder, which is mounted on a pivot that is parallel to the chambers and can swing out and down – usually to the left. Pressing a rod projecting from the front of the cylinder assembly, the extractor pushes all fired rounds free simultaneously. The cylinder can then be loaded and latched in place.
On all4shooters.com we publish articles on revolvers.