Overview of Ammunition for the Novice

by Vaquero

Table of Contents
Fixed or Self-Contained Ammunition
Elements of Ammunition
Caliber
Nomenclature
Cartridge Variables
Arbitrary Divisions
Some Thoughts

Fixed or Self-Contained Ammunition

What it Replaced
As far back as the 1400’s, small arms as well as cannon were loadedwith loose powder and shot. Loose powder was poured into the muzzle end of a gun barrel, and then shot was compacted or simply dropped onto the powder. Barrels of guns of the period were essentially bell-like.That is, they had an open end, the muzzle, and a closed end, the breech, similar to a vase. The powder was invariably ignited from the closed end of the gun barrel, or breech end. This was done through a small ignition hole. The ignition hole was often referred to as a touchhole. A host of ignition devices were created. These devices ranged from touch sticks that were heated iron staves, to slow-burning cords of rope called matches. Later, flint was struck against metal in a variety of ways to provide a shower of sparks that ignited the powder in the breechend of a barrel, usually through a intermediary amount of gunpowder located in a small enclosure called a frizzen pan.

A failure of early arms was that all of the components were not only separate from each other, littering the affair of loading and firing a rifle or cannon with specialized tools, but they were exposed to the elements. Guns used in hunting and martial pursuits are always used outdoors. Loose powder, lighted matches, and ignition powder loaded into frizzen pan all suffer from the deleterious effects of rain, snow and wind.

There were an number of innovations in the 1700’s and early 1800’s in the pursuit of enclosing these fragile elements of firearms, making them weatherproof, as well as easy and safe to handle. The culmination of these early developments is possibly the paper cartridge. The paper cartridge contained the propellent and projectile together in a paper or animal intestine wrapper. It could be roughly handled and exposed to moderate weather without negative effects. Paper cartridges also had the advantage of containing exactly the right amount of propellant, mixed and measured under less trying conditions than a battlefield or hunt.

Enter Smith and Wesson
By the 1840’s the search for reliable and safe ignition of propellant was reaching a crescendo. Two American inventors sewed together a series of overlapping innovations and previous firearm designs into not only one of the first reliable revolvers but also the first successful example ofa gun firing fixed ammunition or metallic cartridge ammunition.

Smith and Wesson’s design utilized a revolver as we understand it today.There was a cylinder that turned whenever the shooter wished to fire a shot. The power that turned the cylinder was provided by pulling the hammer back to a cocked position.

One of the most important parts of the Smith and Wesson pieces was the bored-through holes that ran through the cylindar. These bores allowed fixed ammunition to be loaded from the rear of the cylinder. When fired, the projectile exited the front of the cylinder. The projectile then jumped free bore, or a small amount of open space, and then continued into the barrel.

This is all well and fine, but what exactly is this revolutionary fixed ammunition? First, some common useage problems the uninitiated often find themselves confronted with when attempting to learn about ammunition.

Common Usage Problems
People unfamiliar but willing to learn about ammunition often find themselves confused by the terms they hear bandied about. Why? Probably nine out of ten times the descriptions or technical terms they read or hear are used by people who themselves have little knowledge of the topic. Then, to compound the problem, shooters often use incorrect terminology for ease of speaking. Before we continue with this overview of ammunition, I thought it would be helpful to deprogram you of some false notions. This may help you more easily grasp concepts appearing in the later chapters.

A fully constructed item of fixed ammunition is properly called a cartridge or a round or a shell or a shot. A bullet is the part of the cartridge that is fired from the gun. It is a small element compared to the whole cartridge. Shooters often refer to cartridges as bullets, but the distinction is clear. Properly, a particular gun may hold six cartridges. It is really meaningless to say it holds “sixbullets.”

When one constructs a cartridge that utilizes a particular case, shell,powder and bullet with a known pressure curve (the pressure generated in the firing chamber when the powder ignites), one has a loading. For similar catridges, there are various loadings.

A magazine is a device that hold cartridges. It holds cartridges in place, one on top of another, so that the gun may strip them off and fire them. Not all guns load via magazines. The ones that do are usually autoloaders. Magazines are flat boxes, enclosed on five sides and open at the top. One loads cartridges into the top. Once loaded with a magazine,the gun takes a cartridge from the top of the magazine and fires it. The magazine has a spring in it that pushes the next cartridge in line to the top of the magazine. After a gun fires, it extracts the next cartridge from the magazine. A clip is different from a magazine, and in the modern world far rarer. A clip is a bent piece of metal that holds cartridges in a row. The cartridges are not enclosed in any way like they are in a magazine. Clips are most often used as disposable loading devices for guns, especially rifles, that have built-in magazines. Some guns, however, do accept a clip and use it as part of their firing cycle. The obsolete US service rifle, the M1 Garand, uses a unique style of clip called a bloc that one actually loads into the rifle. The bloc is ejected from the rifle whenthe last cartridge is fired.

Speaking of the guns themselves, some clarification of terms might be required here too.

A machine gun, or automatic, is a gun that continually fires bullets as long as the shooter holds their finger on the trigger. A semi-automatic gun fires one bullet for each pull of the trigger. Comparatively, very few machine guns are in civilian hands. A revolver fires one bullet for each pull of the trigger. A revolver usually holds anywhere from five to nine cartridges, with six being the predominate capacity. An automatic pistol fires one shot for each pull of the trigger. Automatic pistols were given their misleading moniker in the era of their introduction, the turn of the century. An automatic pistol indexes, that is, brings the next cartridge into line for use by the pistol, via the energy of the last cartridge fired. A revolver indexes by the “manual” action of a user pulling back the hammer or pulling the trigger, hence the term “automatic” for autoloading pistols.

There are many more terms that will be defined in the coming chapters. However, with this small base, you will more easily understand the text that follows.

Elements of Ammunition