The Sound Barrier is 1125 FPS at Sea Level
Subsonic Ammunition Doesn't Break The Sound Barrier, Thus No Sonic Boom.
Reduced Noise, Less Recoil, Better Suppression and Less Concussive.
Subsonic rounds have limitations in terms of range, penetration power, and kinetic energy compared to their supersonic counterparts however new ballistic breakthroughs are making it more accurate and quieter than ever!