Bullet & Cartridge Anatomy

A bullet is the projectile. A cartridge is the complete round. These labeled diagrams explain the terminology customers commonly encounter.

The four main components

Simplified centerfire cartridge cutaway. Shapes and proportions are illustrative; the drawing is not a specification or loading guide.

Bullet / projectile

The part that travels down the barrel and toward the target.

Cartridge case

The container that holds the cartridge's other components. Its shape varies by cartridge design.

Propellant

The material whose combustion produces the gas that drives the projectile.

Primer

The ignition component. In a centerfire cartridge, it is located in the center of the case head.

Parts of a bullet

A generic pointed, flat-base projectile shown for terminology. Other designs include rounded or flat noses and different base profiles.

Tip / nose: the front end. Ogive: the curved forward profile. Shank: the cylindrical body. Base: the rear end. These names describe features, not compatibility with a particular cartridge or firearm.

Case terminology you may see

Term	What it describes
Mouth	The open end of an empty case.
Neck	The narrower forward section of a bottleneck case.
Shoulder	The transition between the body and neck on a bottleneck case.
Body	The main wall of the case.
Head / base	The rear portion, where headstamp markings are found.
Rim	The flange at the rear of a case; its form depends on the design.
Primer pocket	The recess in a centerfire case head that holds the primer.

Not every case has a neck and shoulder. Straight-wall and bottleneck cases have different profiles.

For vocabulary and identification only. These diagrams are not to scale and do not provide component dimensions, load data or assembly instructions.