This is a guest post by my author friend, William R. Bartlett. It continues his discussion of all things firearms. Part 1, Introduction, was published in late October. Today, Bill explains how single action revolvers work and describes some common writing blunders. Enjoy and bookmark!
A Writer’s Guide to Firearms by William R. Bartlett
Part 3: Single Action Revolvers
A revolver is a handgun wherein multiple chambers are contained within a cylinder that revolves around the central axis of the cylinder and may be fired multiple times without reloading. Revolver ammunition must be rimmed or, if rimless like most semi-automatics use, placed in a special retaining clip. Since most ammunition for revolvers is rimmed, I’ll concentrate on those.
All revolvers have a barrel, a cylinder, a hammer, and a frame, which includes the trigger and a mechanical device that turns the cylinder when the hammer is cocked. Unlike semi-automatic handguns, revolvers seldom have an external safety. However, most modern revolvers incorporate a passive safety, either a grip safety or a transfer bar that keeps the hammer from hitting the firing pin unless the trigger is pulled. Some modern revolvers come with an active safety in the form of a hammer lock. The cylinder is the revolver equivalent of the semi automatic’s magazine and holds a number of rounds. Most cylinders hold either five or six round, but some smaller calibers can hold nearly a dozen. Some extreme revolvers have been built that hold a ridiculous number of cylinders, but these would require multiple barrels and, when fully loaded, they would be so heavy as to render them virtually useless as a handgun. Some revolvers are called hammerless, but that’s actually a misnomer. The hammer is contained within a shroud above the grip and keeps the spur of the hammer from getting caught in clothing during a rapid extraction from the holster. All revolvers have a gap between the cylinder and the barrel, usually measured in thousandths of an inch. This gap is necessary to allow the cylinder to turn. Some claim this gap causes a decrease in accuracy while others state there is no effect. The gap also keeps silencers, or, more accurately, suppressors, from being effective on a revolver. Some gasses will escape from this gap and make firing the weapon more noticeable in low light situations.
How it works
When the hammer is pulled back to full cock, the cylinder revolves within the frame and aligns a chamber with the barrel. When the trigger is pulled, the hammer hits the firing pin, either directly in older models or indirectly in newer models that have a transfer bar. The firing pin is driven into the primer which ignites the propellant, driving the bullet through the barrel toward the target. A transfer bar is a passive safety and does exactly what the name implies: It transfers the energy of the falling hammer to the firing pin. The normal position of the transfer bar is retracted. Different manufacturers do it differently, but when the hammer is cocked, and the trigger is pulled, the transfer bar is in place to transfer the energy from the hammer to the firing pin, after which it retracts. This keeps the revolver from accidentally firing if dropped. Cocking the hammer again revolves the cylinder and places another chamber in line with the barrel in preparation for firing another round.
Revolvers come in two basic styles: Single action and double action. Single action revolvers like the venerable Colt Single Action Army from the Old West require the hammer to be cocked manually before pulling the trigger. Double action revolvers, like the redoubtable Colt Python, can cock the hammer by simply pulling the trigger. Most double action revolvers can fire single action, that is, by cocking the hammer manually as with a single action weapon. Older revolvers without a transfer bar were frequently carried with the hammer down on an empty chamber for safety purposes. Since the first action upon drawing the weapon from the holster will rotate the cylinder and place a new round into battery, it was considered an acceptable safety precaution.
Operation of Single Action Revolvers
Loading, always the first step in shooting, is not as easy with a revolver as it is with a semi-automatic. In a single action revolver like the aforementioned Colt Single Action Army (aka The Peacemaker), the hammer must first be placed in the ‘half-cock’ position, that is the first click that’s heard when the hammer is drawn back. A spring-loaded loading port cover is opened and a rimmed cartridge (most single action revolvers cannot fire a rimless cartridge) is dropped into the exposed chamber. The cylinder is rotated until the next empty chamber is exposed, and another round is inserted. This process is repeated until all chambers are filled. The loading port cover is flipped back into place, the hammer is pulled to full cock, then, slowly and very carefully, lowered into position. The weapon is now ready for firing. The actual firing is simple. Pull the hammer back to full cock, aim and squeeze the trigger. The chambered round in line with the barrel is fired and goes down range. Repeat the process until the ammunition is depleted. Unlike a semi-automatic, the empty cartridge is not automatically ejected and the spent cartridge must be removed from each chamber before a new round can be inserted. The hammer is again put in half-cock and the loading port cover is opened. A tube on the lower right side of the barrel contains a spring-loaded manual ejection rod with a small tab under the barrel muzzle. Pulling the tab toward the breech will push the spent cartridge out of the chamber. The spring pushes the ejector rod forward and will allow the cylinder to be turned to the next chamber where the process can be repeated until the cylinder is empty of spent cartridges.
Advantages of Single Action Revolvers
They are sturdy and uncomplicated. This is a proven design that dates back to the latter half of the nineteenth century, earlier if one were to include revolvers prior to the development of metallic cartridges. The strength required to pull the trigger is usually less than with a double action revolver. Felt recoil is dampened somewhat by the greater weight of the revolver.
Disadvantages of Single Action Revolvers
Loading takes longer than with a semi-automatic or most double action revolvers. Each individual cartridge must be inserted into a chamber to load the weapon and all of the spent cartridges must be manually extracted after firing before it can be reloaded. The hammer must be cocked prior to each shot. They can be heavy because the frame, barrel, and cylinder with multiple chambers must be made from steel. Because there is no spring or moving slide to absorb energy, the felt recoil can be greater than with a semi-automatic, although the greater weight can ameliorate felt recoil somewhat.
I hope this helps with your writing. The next installment will cover double action revolvers.