Originally Posted By: Snagglefoot
Interesting. The speed of sound is 1126 feet per second. What speed do those bullets travel at? I guess it makes sense that they wouldn’t make the “crack” noise from going supersonic. Are they pretty effective in suppressing the noise?
If you've ever been in the Butts at a target range, you can hear the sharp crack of the bullet passing overhead before the bang of the rifle firing if things are supersonic, and still supersonic over the top of you. If they drop below sonic in flight, you'll either get the report after or before seeing the hole depending on how fast they started.
Target .22 Ammo is intended to be as fast as it can be and still be under the trans-sonic region, so as to maximise accuracy. Once you hit the trans-sonic range, drag increases greatly, and as a result, wind drift increases markedly, and stays higher until serious supersonic speeds are attained.
There's a weird phenomenon in that range, where the "delay" time (true time of flight - time of flight in a vacuum) is greater for the supersonic than the subsonic...it gets there faster, but is delayed longer.