Summary
- Subsonic 9mm ammunition is designed to operate at a speed below the speed of sound, generally between Mach 1 and 343 m/s.
- Subsonic ammo reduces recoil, making it an excellent platform for beginning shooters or those who train and compete regularly.
- Subsonic bullets reduce sound by eliminating the supersonic crack and muzzle blast components of the gunshot noise.
- Subsonic loads work well with suppressed firearms, resulting in a very quiet firearm.
What is Subsonic 9mm Ammunition?
The term “subsonic” is used to describe ammunition that does not produce a sonic signature. Subsonic ammunition is specifically designed to operate at a speed below the speed of sound. Generally, this speed is between Mach 1 and 343 m/s, or 1100 FPS, to avoid the supersonic velocity shockwave. Bullets that exceed this speed cause an extremely loud shot.
Subsonic Ammo Reduces Recoil
Subsonic 9mm ammunition has much less recoil than standard ammunition. This makes them an excellent platform for beginning shooters or those who train and compete regularly. It is also a great choice for competition shooting because of its lower recoil. This makes it easy to make follow-up shots. In fact, 95% of rounds shot in USPSA competitions are subsonic, with 147 grain bullets accounting for 47% of all loads. Many competitors also notice that subsonic ammo tends to run cleaner, with less powder burn.
Subsonic Bullets Reduce Sound
Subsonic 9mm ammunition uses heavier bullets and a lower powder charge, resulting in a lower muzzle velocity. This eliminates the supersonic crack and muzzle blast components of the gunshot noise, two of the most common sources of noise. As a result, the gun will run quieter without the need for a suppressor.
Subsonic Loads Work Well with Suppressed Firearms
This type of ammunition also works well with suppressors. These suppressors dampen the muzzle blast and reduce the sound of the round as it heads downrange. Although suppressors can greatly reduce gunshot noise, the resulting sonic boom is still substantial. When you combine subsonic ammunition with a suppressor, then you have the best of both worlds and one very quiet firearm.