Speed of Sound Calculator

[Rumbler]

It pleases me to see so many folks starting to migrate to - or at least experiment with - the 300 AAC Blackout.

If you are one of those folks, you realize the versatility of the platform. Particularly it's ability to shine on both ends of the velocity spectrum, subsonic (particularly suppressed), and supersonic.

Supersonic is easy. So I don't feel the need to talk much about that. With readily available recipies it'll equal or surpass the 7.62x39 cartridge in terms of exterior ballistics. What more needs to be said.

Subsonic is a little stickier proposition. At least in my experience. For starters what is REALLY the sonic threshold? Sure, there are some "standard" answers. But reality is that in practical application they are most often wrong. At least for me, it is pretty depressing to load a batch of subs and go shoot them only to hear that unmistakable "crack" as they go supersonic over the chronograph which says they SHOULD BE subsonic. And pretty frustrating to think that I have learned from that, go make a batch with a little less powder and find it will not fully cycle the bolt.

Trust me, that sux.

Soooooooooooo, this experience sent me on a quest to learn WFT was going on with that speed of sound thing. To that end I learned something . . and shit:

1) Altitude really doesn't have diddly squat to do with the speed of sound. Temperature does.
2) There is a really handy online calculator that does all the math for you!!!

http://www.sengpielaudio.com/calculator-speedsound.htm


Enjoy.

[FLT]

Yes. The peak pressure doesn't increase but the dwell time increases .