Subsonic vs Supersonic Ammunition (What's The Difference?)

Published on July 11, 2023
Duration: 12:34

This video explains the fundamental differences between supersonic and subsonic ammunition, focusing on velocity relative to the speed of sound. It details how subsonic ammunition significantly reduces firearm noise, particularly when paired with a suppressor, by eliminating the sonic crack. While offering advantages in stealth, subsonic rounds generally have reduced range and terminal ballistics compared to their supersonic counterparts, often due to heavier projectile weights. The instructors demonstrate these concepts with various firearms and ammunition types, highlighting practical applications and considerations like barrel length.

Quick Summary

The key difference between supersonic and subsonic ammunition is velocity. Supersonic rounds travel faster than the speed of sound (approx. 1100 ft/s), creating a sonic crack, while subsonic rounds travel slower. Subsonic ammo is quieter, especially with a suppressor, but typically has less range and terminal ballistics. Heavier projectiles and reduced powder charges are common in subsonic loads.

Chapters

  1. 00:00Introduction: Supersonic vs. Subsonic Ammo
  2. 00:42Defining Supersonic and Subsonic Speeds
  3. 00:59Ammunition Examples: .45 ACP vs. 5.56
  4. 01:37The Three Types of Firearm Noise
  5. 01:55Advantages and Disadvantages of Subsonic Ammo
  6. 02:04Trajectory and Terminal Ballistics Explained
  7. 02:23How Barrel Length Affects Velocity
  8. 02:50Making Ammunition Subsonic: Weight & Powder
  9. 03:31Visual Comparison: 300 Blackout Supersonic vs. Subsonic
  10. 03:40Range Demonstration: 7.62x39mm Supersonic vs. Subsonic
  11. 04:01Range Demonstration: 9mm MP5 Supersonic vs. Subsonic
  12. 05:40Range Demonstration: .22LR Supersonic vs. Subsonic (Calibri)
  13. 06:41Range Demonstration: .300 Blackout Bolt Gun Supersonic vs. Subsonic
  14. 07:24Conclusion: Suppressors and Subsonic Ammo

Frequently Asked Questions

What is the main difference between supersonic and subsonic ammunition?

The primary difference lies in their velocity relative to the speed of sound. Supersonic ammunition travels faster than the speed of sound (around 1100 feet per second), while subsonic ammunition travels slower than this threshold. This speed difference impacts noise levels, range, and terminal ballistics.

How does subsonic ammunition reduce firearm noise?

Subsonic ammunition significantly reduces firearm noise by eliminating the 'sonic crack' or sonic boom that occurs when a projectile breaks the sound barrier. When used with a suppressor, this leaves only the mechanical action of the firearm, resulting in a much quieter shot.

Are subsonic rounds less effective than supersonic rounds?

Generally, yes. Subsonic rounds typically have reduced range and less terminal ballistics due to their lower velocity. However, they often use heavier projectiles to compensate, and their primary advantage is stealth and reduced noise, making them suitable for specific applications like suppressed shooting.

Can barrel length affect whether ammunition is supersonic or subsonic?

Yes, barrel length can influence a round's velocity. A longer barrel provides more time for expanding gases to push the projectile, potentially increasing its speed. This means ammunition designed to be subsonic in a pistol might become supersonic when fired from a rifle with a longer barrel.

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