By John Bibby
Every reloadable cartridge is built from the same four base components. These are primer, brass, powder and projectile.
Primer:
This is a small metal cup containing an explosive. Most US reloading uses Boxer primers. The primers are a onetime use item. As such, the old one must be pressed out of place, using a depriming die and discarded. New ones are pressed into place, using a priming tool, as the first* step of assembling the new round. By placing the fresh primer in the primer cup of the brass, it plugs the hole where gun powder would fall out of the bottom of the case.
*There are often pre-steps of bullet or brass preparation done prior to assembly, but that is not a fundamental step or practice.
Brass:
This is the container that holds all the other components together. Although called “brass,” it can be made of aluminum, steel or brass. For reloading purposed, the only appropriate material to use is brass. Aluminum and steel cases (brass) are one time use items. The cases made of metal other than brass, work harden extremely quickly and have a very strong potential for failing if reused.
Brass must be cleaned. The interior of the brass will often have a layer of carbon fouling, the primer pocket may also be dirty. The case must also be resized, as the firing process changes the shape of the case and the neck. Caliber specific dies are used for this process.
The brass must also be checked for total length after the resizing process. This is especially important for bottleneck cases, as the firing of such cases stretches the neck length. This stretch increases the total length of the case. If that creates a case longer than the maximum standard, using that piece of brass can cause severe issues. Severe over pressure rounds are the most common issue. This over pressure can create case head separation, burst brass and even rupture of the action. The good news, there is a tool that makes trimming the case back to specification a simple process.
Powder:
“Powder” is shorthand for gun powder. Gun powder comes is at least 200 application specific formulations. The basic delineation lines with gun powder are if they are single or double base propellants. There are formulations designed for the pressure curves needed by shotguns, pistols and rifles. These different characteristics are created using powder shapes as well as chemical additives to slow or increase combustion speed as well as how efficiently the powder burns.
The primary three shapes for powder are ball, flake and stick. Just like their descriptors suggest, the ball powders are small spheres of powder. Ball powders tend to burn slower as they are denser with less exposed surface area but are very easy to accurately meter. Flake powders tend to meter much less consistently as they often create a jam in the powder measure. They tend to be much faster burning and have a much quicker pressure spike. Many are pistol powders as the quick pressure is useful in the short pistol barrels. Stick powders tend to meter much better than flake, but less well than ball. They tend to be the slowest burning powders and are normally used in large caliber/magnum rifle rounds. Their slower burn rate is useful in the long, 20-28” magnum barrels.
Projectile:
The bullet is the projectile that strikes the target. Depending on the type of shooting one is doing, the projectile can be shaped/constructed in various ways.
Common examples are:
Solid lead projectile – inexpensive and useful for shooting below about 1200 fps. In applications above 1200 fps, the barrel may accumulate melted lead, creating an unsafe pressure situation. There are options to mitigate that, but most people choose jacketed, plated or coated rounds above 1200 fps.
Jacketed projectiles – a bit more expensive than plated, as a much thicker copper jacket has been swaged over the internal core of lead. In this category, there are many options. Full metal jacket refers to a projectile that has a complete encasing in copper. These may be spire pointed, round nosed or flat. Jacketed hollow points are a copper jacket that covers the projectile except for a recessed area at the front and the thickness of the jacket typically thins towards the nose. This allows for impact expansion of the front portion of the bullet. Jacketed soft points are similar, but they typically do not have a tapered jacket and have a completely exposed lead nose. These work similarly to a jacketed hollow point but use a simpler method of construction. It provides much less reliable expansion, especially at pistol velocities.
Plated projectiles – slightly more expensive than solid lead and effectively a lead bullet that has a very thin layer of copper electroplated over it. This virtually eliminates leading concerns and allow for safe shooting at much higher velocities
Coated projectiles – like plated, but the covering material is often an epoxy base. It is strong enough to keep lead from depositing in the barrel but has little effect other than that.
Within each of these broad categories there are dozens of sub options based on the desired use of the bullet. The needs of a pistol shooter are different than those of a rifle shooter. The shapes of projectiles used for long distance are quite different than those designed for close work. Projectiles designed for defense are very different than those designed for plinking. A little research will help narrow down the choices to ones that are appropriate to the application.
