How fast is subsonic speeds?
Typical speeds for subsonic aircraft are less than 250 mph, and the Mach number M is much less than one, M << 1 . For subsonic aircraft, we can neglect compressibility effects and the air density remains nearly constant.
Is 1000 fps subsonic?
Technically, any ammunition that achieves less than supersonic velocity is in and of itself subsonic, which is 1,126 ft per second. That’s the speed of sound. Anything faster is supersonic, anything at or around that speed is transonic, and anything below that velocity is subsonic.
