Cartridge Variables

The amount of powder, which is measured by weight in grain, is varied in a shell in order to produce different velocities. The maximum amount of powder for a given bullet, or maximum charge weight, is determined by the SAMMI specs concerning maximum pressure the shell is allowed to generate. Within those parameters, bullet performance is empirically measured. Remember, varying the weight of a charge of powder in a loading can only be done for a particular powder. Trying to mix powders of different brands will only lead to disaster.

There are primers made for rifle ammunition and primers made for pistol ammunition. Additionally, primers come in sizes. Reloading manuals will specifically tell you which primer to use for a particular loading. Large primers are used for powders that difficult to ignite.


1. Weight
One variable in a loading is the bullet weight. There is a particular range of acceptable bullet weights. The weight of a bullet, all else being equal, can determine the amount of energy transfered downrange.

2. Shape

Wadcutters are bullets constructed in the shape of little, stubby cylinders. They typically are set flush with the case mouth. Wadcutters are most often used for target practice, since their flat noses punch round, clean holes through paper targets.

Round Nose
Most often thought of by people when conceptualizing a bullet, the round nose shape is typical of older ammunition. It is an all-around shape. The round nose gains some aerodynamics over a shape like the wadcutter. The roundnose is preferred for autoloaders. In an autoloader’s firing cycle, the cartridge is pushed into the firing chamber. The round nose shape facilitates loading.

Spitzers are pointy-nose bullets. Spitzer seems to be derived from the German word spitz which means “pointed.” In German firearms usage, pointed bullets are called “Spitzgeschosse.”(thanks to David J. Moses of VISIER Arms Magazine in Germany for setting me straight that there is no German word “spitzer”, and for supplying the aforementioned info!) Simply, spitzer bullets are pointed. They most often are associated with rifle ammunition. The most famous spitzer round is the 7.92X57MM JS, usually referred to in America as the 7.92 or 8MM Mauser. It was the German military cartridge for both world wars.

A boattail bullet has a bullet heel that reduces to diameter that is less than the largest diameter of the bullet. The boattail should not be confused with an outside lubricated bullet’s heel construction. A boattail bullet is inside-lubricated. The boattail construction attempts to reduce turbulence in the bullet’s wake, keeping it from tumbling at extreme distances.

Semi-wadcutters are like wadcutters in that they have flat noses, but they are longer in shape than the wadcutters, rising some distance past the case mouth. They usually have shoulders at the level of the case mouth. These bullets are used in autoloaders, though can be finicky about chambering.

3. Types of Nose Construction
There are basically two types of noses, hollow points and solid. A hollow point bullet has a cavity tooled into its nose. The cavity is there to aid the bullet in expansion when it is shot into a target. The hollow point bullet will only expand under the considerable stress of being filled with water or flesh; paper or sheetrock or leaves will not expand it. One wants bullet expansion in most combat and all hunting scenarios in order to obtain as large as possible wound channel.

The most famous, or perhaps infamous, hollow point is the Black Talon. Black Talons utilized pre-stressed cavity walls. When the nose was sufficiently impacted upon, the cavity walls would give way in a star pattern. Mainly, the Black Talons could be relied upon to give standard mushrooming or nose expansion. Federal’s Hydra-Shok bullets use a center post along with pre-stessed cavity walls. Upon entering a target, the post conducts materials from the center of the cavity to the walls, aiding in expansion. Further, when the post fails, or bends inwards, it aids in making the bullet yaw, or turn, in the target, giving greater penetration without passing through the target. If you are looking for more about hollow points, don’t. Despite the unmitigated media campaign against them, they don’t do anything else than what I just described.

4. Jackets
Jackets are adhered to bullets to control expansion ofthe bullet, or to aid in feeding in autoloaders. Jackets are usually made from copper and are properly said to made of gilding metal. Many people think jacketed ammunition is armor piercing. It is not. Jackets are made of soft metal than cannot possibly penetrate hard metals or polymers like steel or Kevlar.

A jacket can completely cover a bullet, or only cover it half way up to the nose in a style called semi-jacketed. A bullet that is covered completely by a jacket is called fully-jacketed, a full metal jacket bullet (for short), full-patch, or ball ammunition. Terms like patch and ball go back to musket days. Musket balls were wrapped in a greased linen patch to facilitate ramming them down the barrel as well as aid them traveling under pressure back up. Also, the greased patch helped to clean the barrel of the residue produced by blackpowder. Military ammunition is always fully-jacketed to reduce expansion of the bullet in accordance with the Rules of Land Warfare.

There is also a proprietary version of a full metal jacket called a total metal jacket or TMJ. A TMJ bullet is jacketed at its base as well.

Jackets are adhered to bullets in two broad ways. A jacket, especially for a handloader, can be swaged onto a bullet, that is, squeezed on. A jacket can be electroplated to a bullet as well, or chemically adhered as in nylon jackets.

5. Armor Piercing
We have mentioned what is not armor piercing ammunition. What it is is a bullet with a center post of hardened steel or bronze. The soft lead inside the soft jacket of a bullet will simply crush against a hard metal target. The interior post of an armor piercing bullet will continue to travel forward and attempt to slice into the target’s metal surface. This is the only type of ammunition that will spark against metal since lead and gilding copper are too soft to cause friction sparks. Armor piercing ammunition made for handguns is illegal in the US.

A curious sidebar to this is the Hoaxie bullet, which was a commercially manufactured bullet that had a large hollow point tooled into its nose. Into its nose was inserted two balls of shot. This is considered to fall under the regulation governing armor piercing ammunition, though no one knows why. Incidently, loading one or two balls of shot into the mout of a cartridge in place of a proper bullet is not illegal (nor is it armor piercing).

Arbitrary Divisions