Subsonic vs Supersonic Ammo: What's the Difference?
May 23, 2026 · AmmoBin.com
Subsonic and supersonic describe whether a bullet flies faster than the speed of sound (~1,125 fps). It mostly matters for noise — especially with a suppressor.
The sound barrier
A supersonic bullet creates a small sonic boom — the sharp 'crack' you hear downrange — regardless of any suppressor. Subsonic ammo stays below the speed of sound, so there's no crack, only the muzzle report.
Trade-offs
Subsonic is much quieter (the key to truly quiet suppressed shooting) and often very accurate, but it's slower with a more curved trajectory and less energy at distance. Subsonic loads are typically the heavier bullet weights in a caliber — see grain weights.
For suppressor use, subsonic is the move — see best suppressor ammo. Compare live prices for 9mm and .300 Blackout.
Frequently asked questions
Is subsonic ammo quieter?
Yes — it avoids the supersonic 'crack,' so it's much quieter, especially suppressed. You still hear the muzzle report and action noise.
What's the downside of subsonic ammo?
Lower velocity means more bullet drop and less energy at distance. It's ideal for quiet/suppressed shooting, less so for long range.
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