Important Disclaimers
- This information is for educational purposes only.
- Always follow local, state, and national laws regarding purchase, possession, storage, and transport of ammunition.
- Do not attempt to modify ammunition.
- Safe handling practices are essential whenever ammunition is present, even without a firearm.
- Nothing here is intended to provide guidance on harming people or animals.
What ammunition is
Ammunition (often called “ammo”) generally refers to cartridges or shells designed to be used in compatible devices such as firearms. A typical cartridge includes:
- a case
- a primer
- propellant
- a projectile
This page focuses only on basic terminology and classification, not on usage.
Major categories of ammunition
1. Rimfire vs. Centerfire
These terms describe where the primer is located:
- Rimfire
- Primer is built into the rim of the case
- Commonly used in smaller cartridges
- Generally not reloadable
- Centerfire
- Primer located in the center of the case base
- Most modern ammunition uses this design
This classification is mechanical, not tactical—it simply describes construction.
2. Rifle, Handgun, and Shotgun Ammunition
Ammunition is also categorized by the type of platform it is designed for.
- Rifle ammunition
- Typically longer cartridges
- Designed for use in rifles
- Handgun ammunition
- Usually shorter cartridges
- Designed for use in handguns
- Shotgun ammunition (“shotshells”)
- Uses a shell with multiple small pellets (“shot”) or a single projectile (“slug”)
Disclaimer
Always match ammunition only to the equipment specifically marked for it. Using the wrong type can be dangerous and unlawful.
3. Common projectile types (high-level overview)
This section describes construction, not purpose or recommended use.
- Full Metal Jacket (FMJ)
- Projectile enclosed in a harder metal jacket
- Soft Point
- Exposed lead tip with a metal jacket on the sides
- Hollow Point
- Cavity in the nose of the projectile
Different designs relate to how the material interacts with the target medium (such as ballistic gel in testing environments), but this page does not discuss effectiveness for harming people or provide advice on use.
Caliber and gauge (terminology only)
- Caliber refers to the diameter of a projectile or the internal diameter of a barrel (rifles/handguns)
- Gauge is a measurement system used mainly for shotguns
These are naming conventions, not performance advice.
Safety and legal considerations
- Store ammunition locked, dry, and away from heat sources
- Keep out of reach of children and unauthorized individuals
- Follow transportation guidelines issued by relevant authorities
- Never attempt to disassemble or alter ammunition
- Laws vary widely by location; always confirm legal requirements where you live
What this page intentionally does not cover
To avoid risk or misuse, this page does not include:
- advice on self-defense
- guidance on harming people or animals
- instructions on using or modifying ammunition
- tactical recommendations
- optimization for lethality
Summary
Ammunition types are classified primarily by:
- primer location (rimfire vs centerfire)
- intended platform (rifle, handgun, shotgun)
- projectile construction (FMJ, soft point, hollow point)
- measurement system (caliber or gauge)
Understanding the terminology can help with reading labels, legal understanding, and safety awareness—without providing instructions for use.