Is there a sonic boom upon firing a supersonic round?

[Lazydays]

Unfortunatly,I was in VERY loud helocopters,(UH34D for those who remember) and you never heard the one that hits you. You just thank God that it was only minor for you.

first of all, from one I-Corp rat to another; "welcome home brother!" Been a long time since I heard the can opener sounds of 51 cal ripping thru a Chinook or a Huey. Always wondered how anybody kept their hearing in those UH34's!! What was your AO? I spent most of my time in the Que Son area, but prior to Tet I was just south of Chu lai and got as far south as bronco
gary

 

[Lazydays]

Looking at the asteroid on the news today whose sonic boom caused all that damage in Russia, it occurred to me that since many rifle rounds are faster than the speed of sound, is there a sonic boom? Don't know if it occurs at the same time as the discharge and I may not be able to distinguish it. Or, maybe only objects of sufficient size or mass can cause sonic booms, and maybe the bullet is to small of or insufficient mass. Any thoughts from any of you physicists or physicist wannabes out there.

one of the things you learn in combat is the sound of a gun being fired. You hear a boom and a crack. This helps you to locate who's trying to ruin your day. The crack is the round being fored and the boom is the sonic blast from breaking the speed of sound as the bullet passes by (hopefully).

Now to take the above deeper, let me point out an anomaly. Take a 8" cannon (M110 in this case). It's pretty much against the rules to fire the round with a charge one or charge three (can't remember which one) as the round breaks the speed of sound about four or five feet after leaving the barrel. It will often blow out the windows in any truck or even a car parked nearby. Now that's a 200lb. mass that's about two feet long, and it's gonna create a serious shock wave as it passes low to the ground. Once it gets altitude the problem is moote.
gary

" You hear a boom and a crack"

If you're on the receiving end....the CRACK comes FIRST.....and then if you're lucky...you'll hear the BOOM!!

your right, I'm getting way too damned old these days. What's interesting, and follows the same format is to be on the wrong end of a beehive round. You hear a loud blast, and all this buzzing, but no crack! That happened to me once, and I didn't think right for a month.
gary