A Quick Guide to Understanding the Different Types of Ammunition


In 2021, the global ammunition market was valued at $22.35 billion, and it’s expected to grow from there. That means many people have purchased tons of ammo, whether they were first-time gun owners or enthusiasts who have been collecting guns in the past.

Understanding different types of ammo hawaii is beneficial for firearm knowledge. Some people may get mixed up between a 20-gauge being bigger than a 12-gauge. Others may not know the difference between a clip and a magazine.

If you want to learn about the different types of ammunition, read on.


Caliber is used to describe the internal width of the barrel of a gun, and therefore the ammunition for it.

In the United States, caliber is measured in hundredths of an inch. So a 45-caliber gun uses bullets that are 0.45 inches wide.


In addition to caliber, shotguns are commonly measured in gauges. The higher the number count of a gauge, the smaller the shell. For example, a 20-gauge shell will be smaller than a 12-gauge.

But shouldn’t higher numbers mean bigger? How does it work?

Gauges are determined by how many metal balls can be filled into a barrel to weigh one pound. If there were 12 balls to be filled into a 12-gauge shotgun barrel, it would be one pound. Therefore, a 20- will be smaller.

FMJ (Full Metal Jacket)

Bullets going through the barrel of a firearm will leave some lead residue over time. To slow down the build-up of lead, FMJs are designed to exit the chamber smoothly.

FMJs leave the chamber smoothly, making for a more accurate and higher bullet velocity. Doing so makes the bullet and firearm more efficient. Due to their speed, FMJs are great for competitive shooting.

JHP (Jacketed Hollow Point)

Great for self-defense, JHPs offer protection against any attacker as the bullet expands like a mushroom. As the bullet expands, it causes more pain to the attacker.

JHPs expand, but this type of gun ammunition is good for decreasing the chances of over-penetration, letting it stay inside the target and stop them in their tracks. Since the stopping power is significant, JHPs are excellent for self-defense and hunting.

Due to their reliable usage, FMJ and JHP are among the best ammunition available. If you want to see more about bullets, check it out!


Rounds (or cartridges) are for handguns and rifles. The components that make up rounds are:

  • Projectile: The bullet that travels to the intended target
  • Case: Usually made of nickel, brass, or steel
  • Gunpowder: Used to propel the projectile
  • Primer: Used to ignite the bullet and shoot the projectile

Shot Shells

Slightly different from cartridges, shotshells are intended for shotguns.

  • Birdshot: As intended, it’s used to shoot birds and causes minimal damage
  • Buckshot: Used for large game
  • Slug: Designed for large game and defense, a slug is usually a big piece of metal

Learning About the Types of Ammunition 

These are the different types of ammunition, such as 9mm ammunition, that you need to learn about as a new gun owner. Knowing the differences between a round and shotshell, caliber size, and gauges, you will buy your gun ammunition.

If you find this helpful and want to learn more, check out our site for more.