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.
Is there a sonic boom upon firing a supersonic round?
- Thread starter Cassidy
- Start date
The "sonic boom" can be heard very well when firing an effectively suppressed rifle. There is still a loud crack as the projectile exits the suppressor and along the bullet path while supersonic.
we like to call it a sonic crack. you can tell the difference with 22lr high velocity and subsonic.
here is a good video where you can hear the difference between sub sonic and supersonic 300blackout suppressed.
[youtube]http://www.youtube.com/watch?v=Q5ALp8-d3dQ[/youtube]
[youtube]http://www.youtube.com/watch?v=Q5ALp8-d3dQ[/youtube]
When you shoot a suppressed 10-22 with subsonic ammo and without the recoil buffer modification, the loudest noise the shooter hears is the action cycling, and there is no downrange noise unless you hear bullit impact. With the same rifle and high velocity ammo, the shooter will also hear the sonic crack downrange; at my home range, it appears to the shooter to occur 18-22 yards downrange.
In reality, there us no boom but a continous sound wave following the bullet. We percieve it as a boom or crack due to the speed of the duration relative to our location. Sometimesit appears a few yards out wirh 22 because of the time it takes sound to reach us.
My 300 yard home range has a large hill that causes the sound to bounce back. You hear the boom from the barrel blast , a sizzle sound, then a smack when it hits. Bullet has allready hit, but you hear it about 2 seconds later.
Anyone who has shot still plates in the right conditions, you almost have time duringthe sizzle to raise your head and then hear the smack.
My 300 yard home range has a large hill that causes the sound to bounce back. You hear the boom from the barrel blast , a sizzle sound, then a smack when it hits. Bullet has allready hit, but you hear it about 2 seconds later.
Anyone who has shot still plates in the right conditions, you almost have time duringthe sizzle to raise your head and then hear the smack.
Years ago I shot silhouette here in PA at a range (forgotten which one) that had a fence row parallel to the range. When you shot that side of the range, the echo of the sonic boom as the bullets passed each post sounded like machinegun fire.
Cassidy said:
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
[br]RMulhern said:
+1
timeout
Silver $$ Contributor
Probably get in trouble with PETA but, shot at a feral cat on a guys farm onetime. Had the farmer and another guy there as witness to it. Pulled the trigger, cat went down. We walked over there and the cat was dead as a mackeral, not a mark on it. Sonic boom concussion? I could not explain it.
P1ZombieKiller
Silver $$ Contributor
We were shooting 800 yards one day (just goofing off), and it was REALLY cool to sit back at 700ish yards and you hear a very loud CRACK right in front of you as the bullet goes by, and then you hear the bullet hit the plywood backing board, then you hear the boom of the shot fired from the firing line.
Even as an old man you think it's really cool.
Even as an old man you think it's really cool.
Forum Boss
Administrator
There sure is when you have a meteor entering the Earth's atmosphere at 33,000 miles per hour (48,400 FPS).
[youtube]http://youtu.be/TtOL5OiWTNI[/youtube]
http://www.huffingtonpost.com/2013/02/15/meteorite-streaks-across-russian-urals_n_2691904.html
[youtube]http://youtu.be/TtOL5OiWTNI[/youtube]
http://www.huffingtonpost.com/2013/02/15/meteorite-streaks-across-russian-urals_n_2691904.html
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.