Do bullets make sonic booms?

Sounded like a gun going off whether it hit the target or not.

Whips proved it even sooner.

But engineers didn’t think anything would be hurt when an airplane broke the sound barrier; if anything, they underestimated the effect of a sonic boom. What they did fear – and why it was called a “barrier” – was that the airplane would break into pieces before reaching the speed of sound.

I was curious so I looked up silencer videos on YouTube. The first video that showed up, is an excellent demonstration. It’s of a gentleman firing three rounds of supersonic ammunition from a silenced M14, followed by subsonic ammunition.

I was honestly very surprised at the difference. The supersonic ammunition sounds very much like an unsilenced rifle (albeit maybe a bit quieter) while the subsonic ammunition sounds like little more than an airgun.


Also note that there’s a big difference between an engineering impossibility and a physical impossibility. Today, I might honestly say “We can’t send a man to Mars”, or “We can’t produce economical fusion power”. We can’t do either of those things right now, but eventually, we will be able to. Likewise, an aeronautical engineer might, at some point, have said that supersonic flight was impossible, but that would just mean that it was impossible with the technology of that moment, not that it would inherently remain impossible for all time.

They’re also cited as being useful for law enforcement, room-clearing, and house to house fighting because when used with appropriate ammunition you don’t need to use hearing protection.

I could into a lot of detail but I am a huge aviation buff and the move to supersonic speed on the Bell X-1 with Chuck Yeager at the controls has always been considered a huge accomplishment. Many engineers thought that the aircraft would be destroyed at the sound barrier although the designers of the X-1 would sure that the aircraft could take the stress.

Independent entries like Slick Goodlin asked for millions or dollars in today’s dollars to press the envelope. Chuck Yeager broke the sound barrier by accident on a flight pushing the all the instruments off-scale and then landing safely. He produced the world’s first sonic boom from a manned vehicle proving it can be done.

Subsonics, a suppressor, and a good scope are also an excellent mix for dealing with a pack of wild dogs for country dwellers.

refer to earlier pit thread about ppl dumping dogs forcing them to become feral to survive.

And they feared it with very good reason, given the number of planes that lost control or simply came apart during WW2 when they got up to high speeds and encountered compressibilty and other related phenomena.

Going supersonic and going supersonic while maintaining control are entirely different things, so a supersonic bullet didn’t prove much. Flight at close to sonic speeds poses a number of problems due to the way the pressure changes around the flying and control surfaces. Control reversal and uncontrollable pitch moments are a couple of symptoms. Modern airliners use various engineering solutions, suffice to say that getting too fast in an aircraft not designed for it can be a bad thing.

It wasn’t an accident. They were not surprised by the sonic boom because they expected it on that flight. If they hadn’t Yeager likely would have found a way to reschedule the flight since he had broken ribs. He simply wanted to be the person to do break the sound barrier.

Unless we’re thinking of two totally different things portingon a gun barrel does nothing to make them quieter, as a matter of fact a ported gun is usually louder than it’s normal counterpart. Porting is done to reduce felt recoil to the shooter on larger caliber handguns.

No. Maybe I wasn’t clear. I was thinking about designs which have ported barrel inside extended silencer sheath - so gases are leaving the barrel, but are contained within silencer.

Interesting. I’m going to look that up.

Wiki page about HK MP5 have diagram showing silencer like this.

the crack is followed by the thump from the gun that fired it.
There is a noticeable gap between the two by about (say) 300 yards.
At about 1200 yards the 7.62mm NATO cartridge falls to about Mach 1 or less and incoming bullets are harder to notice when you are doing the target marking

That’s a special design that’s meant to do two things: 1) Reduce a standard supersonic bullet to subsonic by the time it comes out the end of the barrel so that you don’t get a sonic boom from the round, and 2) Suppress the sound of firing at the source. Firearms like those are designed from the beginning to be permanently suppressed. Since the market for those is pretty small, and the design work is exacting, there aren’t all that many models produced. After-market suppressors for standard firearms are far more common. The MP5 is probably the most famous and widespread weapon with an integral suppressor. Ruger also makes a couple of rifles with integral suppressors. There are probably a few more, but since I’m not exactly an expert I don’t know all of the offerings out there.

My experience of rounds passing my close vicinity is the sound of an incredibly loud CCCCUUURRRACK, if you are alert to it you also usually hear shortlly after a dull "toomp"from the direction of the firer.

We talked about supersonic and subsonic ammo just about two months ago, in this thread: (Gun) Silencers: How loud, really? And related…

For those who don’t care to read the other thread: the speed of sound in normal air conditions is about 1130 feet per second. It appears that the most popular handgun cartridges (.38, .380, 9mm) are subsonic, but there are plenty of supersonic cartridges out there, and those will indeed produce a little sonic boom. For example, the two calibers I shoot, .40 S&W (155 gr, 1275 fps) and .357 SIG (125 gr, 1475 fps), are supersonic.

I think most 9mm ammo, including standard NATO ammo, is supersonic. The subsonic stuff is loaded with extra-heavy bullets (147 gr).

Hate to hijack this thread…

But according to things I’ve read, the X-1 WASN’T the first aircraft to go supersonic, it was the first to do it in LEVEL flight. Other aircraft had passed the sound barrier it in a dive, so the sonic boom wasn’t a completely unknown phenomena. You might note that most every record listing for the X-1 has the key words “level flight”

Level flight is an important distinction of course, but I thought I should point that out.

One cite I found:

The only problems with these supersonic flights is that they weren’t “official”.