Supersonic and Subsonic Ammunition when Shooting Suppressed

Understanding Supersonic and Subsonic Ammunition: Choosing the Right Ammo for Suppressed Shooting

If you’re considering purchasing a suppressor or you're already the proud owner of one, you’ve likely come across the terms “supersonic” and “subsonic” ammunition. These terms are critical to understanding how suppressors work and how they affect your shooting experience. Choosing the right ammunition not only enhances your suppressor’s performance but also ensures that you’re getting the most out of your firearm.

In this post, we’ll break down the differences between supersonic and subsonic ammunition, their pros and cons for suppressed shooting, and some key things to consider when selecting ammo for your suppressor.

What is Supersonic and Subsonic Ammunition?

At its core, whether ammunition is supersonic or subsonic depends on the speed at which the bullet travels. Sound travels at approximately 1,125 feet per second (fps) at sea level, also known as the speed of sound. Bullets traveling faster than this are considered supersonic, while bullets traveling below this speed are considered subsonic.

• Supersonic Ammunition: This type of ammo exceeds the speed of sound. It creates a small shockwave, known as a sonic boom or crack, as the bullet breaks the sound barrier. Examples include the widely used .223 Remington or standard 6.5 Creedmoor rounds.
• Subsonic Ammunition: Traveling at velocities below the speed of sound, subsonic ammo doesn’t produce the sonic crack, making it inherently quieter when paired with a suppressor. Common examples of subsonic calibers include .300 AAC Blackout (subsonic loads), .45 ACP, and many .22LR rounds.

How Suppressors Work with Supersonic and Subsonic Ammo

A suppressor (or “silencer”) reduces the noise and muzzle blast of a firearm, but it can’t suppress the sonic crack of a supersonic bullet. Let’s take a closer look at how suppressors perform with each type of ammunition:

1. Suppressors + Supersonic Ammunition: When using supersonic ammo with a suppressor, the suppressor effectively reduces the sound of the gunpowder igniting and the pressure escaping the muzzle. This dramatically quiets the initial “bang” of firing. However, you’ll still hear the distinctive crack of the bullet as it breaks the sound barrier. While supersonic ammo isn’t completely silent, the combination of a suppressor and ear protection makes it much more manageable and can dramatically reduce hearing damage. Many hunters and long-range shooters prefer supersonic ammo for its ballistic advantages, despite the sonic crack while shooting suppressed.
2. Suppressors + Subsonic Ammunition: Combine a suppressor with subsonic ammo, and now you're talking quiet. By keeping the bullet’s speed below the sound barrier, the suppressor eliminates the muzzle blast without the added crack of supersonic travel. This makes subsonic ammo ideal for stealth applications, shooting in residential or noise-restricted areas, and general backyard plinking, your neighbors will thank you. With some calibers, like subsonic .300 Blackout, the result can be so quiet that the loudest sound you hear is the cycling of the firearm’s action.

Pros and Cons of Supersonic vs. Subsonic Ammo for Suppressor Use

When deciding between supersonic and subsonic ammo for your suppressed firearm, consider the following:

Supersonic Ammunition:

• Pros:
  • Greater velocity and flatter trajectory, making it ideal for long-range shooting.
  • Higher kinetic energy, providing better penetration and terminal performance for hunting and defense.
  • Widely available in a broad range of calibers.
• Cons:
  • The sonic crack cannot be suppressed.
  • Louder overall, even with a suppressor.

Subsonic Ammunition:

• Pros:
  • Incredibly quiet when suppressed—excellent for stealth or noise-sensitive environments.
  • Reduced recoil due to lower velocities.
  • Ideal for short-range applications.
• Cons:
  • Lower velocity can result in limited effective range and bullet drop over distance.
  • May have less energy at impact, reducing effectiveness for hunting or self-defense in certain calibers.
  • Can be harder to find or more expensive depending on the caliber.