Different Types of Handguns and How They Work

A single, complete round of ammunition is composed of the following four items:

  1. The bullet: Although many people call a complete round or cartridge a “bullet,” strictly speaking it refers only to the piece of lead that is held in the front of the casing. Attempting to buy a “box of bullets” in a gun store will result in a box of bits of lead, and not fireable cartridges.
  2. The casing: Most often made of brass, this holds the bullet, crimped in the front of the casing, and is filled with a measured amount of powder.
  3. The powder: This burns very quickly — it does not explode — and the pressure of the resulting expanding gases pushes the bullet out of the casing, down the barrel, and out of the gun.
  4. The primer: A chemical compound which sparks when struck. This spark then ignites the powder.

When the trigger of a handgun is pulled, the spring-loaded hammer at the rear of the gun is propelled forward and strikes the firing pin. The pin then strikes the primer. This causes the primer to spark, which ignites the powder. The powder then burns very quickly, and the expanding gases push the bullet forward into the barrel.

Once in the barrel, the bullet, made of soft lead, engages a series of grooves that spiral down the inside of the barrel, called the rifling. These cause the bullet to spin like a well-thrown football. The bullet then exits the handgun spinning; this gives it extra needed stability to insure that it will go where it has been aimed.

Types Of Handguns


How this all takes place depends on the kind of handgun you have. A revolver, which is what most people think of when they think of a handgun, keeps the now-empty casing in the cylinder, the round section that was swung out of the handgun’s frame and loaded with fresh rounds prior to firing. (Typically, the cylinder will have six chambers, or spaces in which these rounds are placed — a “six-shooter.” Other revolvers which have 5 and 9 chambers in their cylinders are not uncommon.) Pictured is the Taurus model 85.

When all six rounds have been shot and the six empty casings are left in the gun’s cylinder, the shooter then presses a cylinder release latch, swings the cylinder out, and presses the ejector, which pushes the empty casings out of the gun so that it can be reloaded.

Revolvers can either be single-action, or double-action; which one depends on what the trigger is designed to do. In double-action revolvers, pulling the trigger back will cause the hammer to lift, then fall forward and strike the firing pin. The trigger thus performs two tasks: cocking the hammer (lifting it back), and releasing it.

The trigger on an exclusively single-action revolver, however, is not designed to lift the hammer before releasing it. This kind of revolver must therefore be cocked manually, using the thumb, every time it is fired — like the cowboy six-shooters in Old West movies. (Rent “Silverado” and watch Kevin Costner’s hands as he shoots up the stairs outside the jail in Turley. You can see his thumbs working the hammer every time he shoots — in fact, you can see this whenever any of the actors shoots. Trust me, you’ll like the movie, too — it’s not some macho preposterone-laden crap. Four sensitive cowboys have adventures and relate to each other in a really loosely-plotted movie. And you get to see Scott Glenn in leather pants and high-heeled boots. :-)) As a result, these revolvers are clumsy, slow, and very poor for defense, although fun to shoot.

Most double-action revolvers can be fired in single-action mode, however — simply by cocking the hammer manually. Other revolvers are permanently double-action — either because they have internalhammers, or hammers without spurs, so that the shooter cannot cock them prior to shooting.


Autoloaders, also called semi-automatics, are a bit more complex; they employ an ingenious system to eject the spent casing from the gun automatically. The most obvious difference between revolvers and autoloaders is that the latter is flat-sided, without the round cylinder of the revolver. Instead of loading it by swinging out the cylinder and putting rounds in the chambers, a container called a magazine, about the size of a small TV remote control, is filled with rounds and then pushed up into the handgun’s grip. (Taurus’s model PT 58 is pictured.)

When the trigger of an autoloader is pulled, the hammer falls forward and begins the process by which a bullet finally exits the handgun. After this, the pressure of the expanding gases pushes the slide on the top of the handgun back as the bullet leaves the gun. In this manner, a hole in the slide called the ejector port is lined up with the spent casing, and the ejector automatically pops the spent casing out the hole and out of the gun to land a few feet away from the shooter. A stiff spring in the bottom of the magazine then pushes the next round into the chamber to be fired, and the entire process starts over again. All of this happens in the merest fraction of a second after the trigger is pulled, almost faster than the eye can follow.

(This also explains the difference between a semi-automatic firearm and an automatic one. A semi-automatic loads a new round by itself after the first one has been shot (the spent casing is automatically popped out of the gun, and a fresh one takes its place). However, the trigger must be pulled once for every round fired. An automatic, however, fires round after round as long as the trigger is held down, like those big rifles that suck up belts of ammunition in old WWII movies.)

The terms single- and double-action apply a bit differently to autoloaders than to revolvers. In many of these handguns, the slide acts to cock the hammer as it is moving back each time the trigger is pulled. Thus, even though the handgun can be fired in double-action mode (with the hammer down), it is effectively in single-action mode after the first shot. An exclusively single-action autoloader is not as slow and cumbersome as a single-action revolver, however. Although the trigger on a single-action autoloader is not capable of cocking the hammer, the slide performs this function handily.


Derringers are the tiny handguns similar to that used to assassinate Abraham Lincoln, shown at left. A derringer has neither the rotating cylinder of a revolver nor the spring-loaded magazine of the autoloader. Indeed, it has no mechanism for putting a fresh round in front of the firing pin: it is designed to shoot one round only. To load a derringer, the barrel of the gun is swung down from the grip at its hinge, allowing the shooter to place a fresh round inside. The barrel is swung back into place and the gun is then fired. It must be opened again, the spent casing picked out by hand and a new one put in its place, before it can be fired a second time. (Some derringers, with two barrels and a separate trigger for each, can fire two rounds before being reloaded.)

Such guns are often very small and designed to shoot only the smallest caliber of ammunition — the tiny .22 and .25 rounds. Since they often shoot only one round at a time (and the weakest rounds to boot), they have been traditionally regarded as dueling weapons (where you are permited to shoot only one round), or as “ladies'” handguns (heaven forbid we should give an attacker anything worse than a boo-boo). For defense purposes, derringers are utterly worthless, good only for collectors. Don’t waste your time or money on these handguns as defensive firearms.

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The Types of Ammunition

There are many complex-sounding numbers associated with different kinds of ammunition, and they can be daunting and arbitrary at times, particularly those associated with longarms — rifles and shotguns — which are ridiculously cryptic. The most common kinds of ammunitions used in handguns, however, are much easier to understand. Characteristics such as

* bullet size,
* cartridge strength,
* bullet shape, and
* bullet jacketing

all contribute to description of the ammunition.

* Bullet Size

Simply speaking, the caliber of a round most often refers to the bullet’s diameter in inches. A .22 round is 0.22 inches in diameter, fairly small. A .45 round is 0.45 inches in diameter — just under a hefty half-inch across. A 9mm round, a caliber comparable to the .38 which originated in Europe, is 9mm in diameter — larger than a .22 but smaller than a .45. A handgun is called by the caliber of the most powerful ammunition it is designed to shoot (more on this later); thus, a handgun designed to shoot .45 caliber rounds is called a .45 caliber handgun.

However, it can’t all be this simple (of course). There are deviations from this rule that seem confusing at first, but are fairly easy to understand. One of the most common calibers of handgun ammunition is the .357 Magnum. You might expect that this is a different diameter from the .38, but in reality, they are both the same size — around 0.36″ across.

* Cartridge Strength

Another characteristic of a round is the amount of powder it contains. This is often designated by a letter or word after the number. For example, .22 caliber rounds come in .22-short, .22-long, and .22-long rifle (.22S, .22L, and .22LR), which refer to the lengths of the casing and hence the powder contained and the strength of the ammunition. There are handguns designed to shoot all of these.

The common .38 caliber rounds, an excellent choice for a defensive handgun, can be any of the following:

  • .38-Special (.38Spl), the basic, most common variety of .38.
  • .38-plus-P (.38+P), with more powder and hence more punch than a .38Spl.
  • .38-plus-P-plus (.38+P+), with yet more powder.
  • .38 Regular (.38R), archaic and not easy to find. This caliber was designed in the mid-1800’s and was quickly replaced by the .38Spl.

The next step up in cartridges of this diameter is the .357-Magnum (which, despite the different number, is the same diameter as the .38). Considered a different caliber of ammunition even though it is the same diameter, it holds quite a bit more powder than the .38’s and is held in a longer casing. Since the cartridge is longer overall, most .38 revolvers cannot hold or shoot .357M cartridges, although a .357M revolver can hold and shoot .38’s handily. This is not dangerous — .357M revolvers are meant to shoot both .38’s and .357M’s.

Magnums exist in many calibers suitable for defense. There are .357M and .41/.44M (9mm and .45, the other popular defense loads, do not have Magnum calibers).

* Bullet Shape

There are many different kinds of bullet shapes; this primer will go through the most basic ones that a knowledgeable gunowner should be familiar with. The basic types are:

  1. ball or round-nosed ammunition: the type that most often springs to mind when people think of bullets, with a round nose. Touted as more humane, and required by the Geneva Convention in warfare, it penetrates dangerously due to its small surface area and can easily pass through a target to endanger people or objects behind.
  2. wadcutter ammunition: flat-tipped ammunition where the front of the bullet is literally flat across the casing. This was used to score shooting matches when it was seen that ball ammunition tore jagged holes in the paper. Wadcutter ammunition acts like a paper-punch, making neat holes that are easier to score. A further refinement of this type of ammunition is semi-wadcutter, in which the front of the bullet looks like a cone with the tip cut off. The front of the bullet is still flat, but the tapering tip makes it load into revolvers and feed into autoloaders more easily.
  3. hollowpoint ammunition: where the front of the bullet is hollowed out. The shape of the bullet makes it mushroom out when it hits a target, increasing its surface area dramatically. As a result of this, it is almost guaranteed to come to a stop inside the target and not pass through to endanger someone or something behind. There are various refinements on this basic design, such as rounds that expand into a shape similar to a five-petaled English heraldic rose, called Starfire rounds, and Hydro-shock rounds, with a little tongue of metal inside the hollow tip to improve the mushrooming effect. Another refinement is the Black Talon, surrounded by more media hype than the round merits. The Black Talon’s single departure from the standard hollowpoint design is that it is coated with a black metal which expands into sharp petals surrounding the mushroom shape. Supposedly, these petals do more damage to the target than simple hollowpoints, but the damage is not appreciably greater. They are often claimed to go through targets “like buzz saws,” since handgun bullets rotate as they travel. However, in reality, any round will complete much less than one rotation passing through something the size of a person. Black Talons do not increase the stopping power of the standard hollowpoint by much.
  4. frangible ammunition: Even more esoteric than the 1,001 variations on the hollowpoint design is this bullet type. Instead of the typical little lead pellet at the end of the casing, what is there is a little brass cup with a bunch of metal fragments inside, capped with a plastic tip. When the cup is blown out of the casing and impacts the target, the plastic tip is pushed inside the cup and the metal fragments are released. These are guaranteed against ricochet and overpenetration (passing through the target) and are also a “hot load”: since they are lighter than conventional lead bullets, they must be given quite a kick to perform properly. More on these in the defense section of the page.

Following this convention, “.38Spl semiwadcutter hollowpoint” ammunition is that which is roughly .38″ in diameter, filled with the least powder of the various .38 rounds, and shaped like a truncated cone with the front hollowed out.

* Jacketing

Although the bullet itself is made of lead, it may be coated with a thin layer of other material. Shooting a handgun or any firearm invariably involves cleaning it later, and a considerable part of that cleaning process is removing “lead fouling” in the barrel — bits of lead which have been stuck to the inside of the gun due to the soft bullet scraping along either the forcing cone — the first part of the barrel that the bullet engages, slightly tapered so that the bullet can slip into the barrel and engage the rifling grooves more easily — or the rifling grooves themselves. One way of solving this problem of lead fouling is to “jacket” the bullet in another material which will not prevent the bullet from engaging the rifling grooves. (The most common material is copper, although other easily shaped metals can be used as well. One such brand of ammunition is called Ny-Clad and employs a nylon coating.)

There are varieties of jacketing — those that do not cover the very tip of the bullet, and those that cover every bit of the bullet, called “full” or “total metal jacket,” and sometimes denoted by FMJ or TMJ on the round.

In summary, you want to note these four characteristics of a round:

  1. diameter,
  2. amount of powder or strength,
  3. bullet shape, and
  4. bullet jacketing.

and that should suffice to start. Thus, a .357M SWCHP FMJ round is:

  • around .38 inches in diameter,
  • the most powerful round of its diameter,
  • holds a bullet that is shaped like a cone with the tip cut off with a hollow nose, and
  • that is coated in metal, most likely copper.

Other Stuff

Cartridges also differ in where they place the primer. .22 caliber rounds most often have the primer inside the little rim at the rear of the casing; this is called a rimfire round. Most other calibers have the primer in a little depression in the rear center of the casing; this is called a centerfire round.

There are other types of ammunition that you may have heard of — teflon, or “cop killer” bullets are familiar terms. The proper term for such ammunition is armor-piercing ammunition. Despite its media name, of “cop killer” since they can pierce body armor (bullet-proof vests), armor-piercing bullets have been sold only to law-enforcement agencies practically for as long as they have been around, and nopolice officer to date has been killed with an armor-piercing round while wearing body armor. Also, despite their “scary” name, most police officers prefer to use hollowpoints for their superior stopping power.

Can A Handgun Shoot More Than One Caliber?

Sometimes a handgun can shoot more than one caliber; this depends on the robustness of the handgun itself. The gas pressure generated from the burning gunpowder is extremely large — shooting a round more powerful than the handgun is designed to handle can result in damage or injury since the gun may not be able to withstand the greater pressure. For example, a shooter who owns a handgun rated to shoot only .38Spl must never load her gun with .38+P or .38+P+. (Since the casing is larger, the .357M will simply not fit in a .38 handgun.) A .357M however can shoot any of the .38/.357M rounds safely. A .44M handgun can shoot both .44M and .44Spl.

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