IMO firing a supersonic bullet gives two 'cracks', one of breaking the soundbarrier of the bullet after leaving the muzzle and one of the escaping gasses (blast). The hunter hears only one, as everybody knows.
If you're position is at some distance from the hunter, say 200 yards or more, what do you hear, one crack or two, the second a split second later? If you think to hear two cracks, I guess the interval between these two will always be the same, whatever distance you are standing, because both cracks come to you with the speed of sound. Correct?

In my question I do not mean the sound interval of firing and the bullet impact after hitting the animal. This sound depends on the distance you are hitting, obviously. But in this case, is there also a composition 'boom' of the impact and the bullet returning to below the speed of sound?
Please your expert advice.
Nice day,
Jan.

Well, I'll give this one a shot. If you were downrange at say 200, you would hear the that sound first, as the bullet is traveling faster than the speed of the sound of the gas escaping, which is traveling about 1150 fps. Depending on the caliber, that bullet is moving at twice that speed, like 2500 fps on up to 4000 fps. But 200 yards is really too close to discern the difference.

The farther you go down range, the longer the interval between the bullet arriving and the sound of the shot from the muzzle. So if you are standing down at 800 yards, (~2400 feet)and you get shot, you theoretically could be dead before the sound of the escaping gas even gets to you, as it will take better than 2 seconds for that sound to reach you, while the bullet is there in about 1 second.

Longer distances increase the spread between bullet arriving and muzzle blast arriving.

The further away I am, within hearing distance, I hear 2 distinct sounds. Very hard to describe a sound but what I hear is much like

ka-boom, and if I'm really far away it sounds more like a ka-wollop.

standing behind a protective berm in the pits,
@100 yds i hear a loud snap and boom.
@600 yds its a medium snap then about 2.5 seconds later the boom.
@1000 yds the snap sounds like a someone saying sccccccct very fast,then the boom 4.5 to almost 6 seconds later.
regards

Hey you guys just don't shoot enough if you can hear.

quote:

Originally posted by ramrod340:
Hey you guys just don't shoot enough if you can hear.

roger

I simply hear as well as feel the sear moving then the hammer or firing pin traveling . Then it's BOOM ! or Crack ! Dependant upon caliber .

From then on it's all feel because the second shot if I take one is something my ears don't really register . Yes I hear Boom or Crack but not like I do on the First shot . I also don't flinch after the clean out shot .
As DOC says Ka - Wallop if I'm listening to some one else far away shooting .

Shoot Straight Know Your Target . ...

quote:

Originally posted by jjmp:
standing behind a protective berm in the pits,
@100 yds i hear a loud snap and boom.
@600 yds its a medium snap then about 2.5 seconds later the boom.
@1000 yds the snap sounds like a someone saying sccccccct very fast,then the boom 4.5 to almost 6 seconds later.
regards

Ditto that! Something else that can be heard overhead on a long shot is the "swish" of the bullet's supersonic flight. For those of you who hunt in the hills, you know what I'm talking about. When solid bone is hit, the impact can be heard at some distance too. At other times, like when its snowing, not much of anything can be heard.

When I'm on my range's "auxiliary range" up the hill some 100 yards behind the rifle range's firing line, whenever someone shoots a centerfire rifle I hear a "whoosh" after the boom of the muzzle blast, produced by the turbulence behind the base of the bullet. With a big Magnum shooting at 200-300 yards it's very noticeable, reminding me of a jet.

A while back I had the opportunity to fire someone's suppressed black rifle with M193 55gr bullets loaded subsonic with a small charge of a pistol powder. The firing of the rifle made no more noise than the sound of the striker falling on a dry fire, but I was amazed how loud the whoosh of those little FMJBT bullets flying downrange at subsonic speed was. With full power loads it was far quieter than an unsuppressed rifle, but still pretty loud. Interestingly, we found it was quieter with a .308 suppressor on the .223 than with the .223 one.

I might be wrong in my own interpretation of the question, but..

Considering the OP's original question: Would a person, standing downrange, hear both the sound of the rifle firing AND hear the sound of the bullet breaking the sound barrier??

I would say, No. I don't think the sounds would be seperate. Reason beiong that the bullet is supersonic before it leaves the barrel, so the sonic boom and muzzle blast would be combined as one.


I agree that there is a definite "sound" a bullet makes as it travels downrange, but I don't think that's what the OP was originally asking.

Thank you for your input. To start with 284Win: yes, you're right. So a creature, shot in pursue of something interesting, would not hear any sound, because the bullet strikes before the sound of the muzzele blast can reach it. Clear.
As Doc says, he will hear, depending on the downrange distance, a KA-BOOM, or, further away KA-Wollop. Interesting, because this means he thinks he hears two sounds, the sound barrier breaking and the blast, may be(?).
JJIMP hears two sounds at a definite interval, depending on the distance downrange. This could mean he hears the flight of the bullet and some seconds later the escaping gasses from the muzzle. But this can't suggest that he hears the difference in interval between sound barrier and blast, if I'm right.
I think Charlie got my question. I think the braking of the sound barrier can only be heard after the moment the bullet leaves the muzzle, but it is true that the bullet reaches its maximum (super sonic) speed inside the barrel. So it leaves the muzzle at sound barrier plus speed. But only at that moment, the crack can be heard, IMO. And this is practically at the same moment as the blast. If Charlie is right, you can only hear one compound sound, in front of the rifle as well as some 1000 yards at a right angle or even behind the rifle. All the other sounds find their origin in the flight of the bullet, the echoing, or whatever. Right?

But what when the bullet gets a velocity below the sound barrier (after hitting), just like an F16 coming from super speed and slowing down, giving an enormous 'bang'. Does this loss of bullet speed contribute to the sound of the bullet impact? Or, to put it another way, if you fire a super speed bullet vertically in the blue sky, will you hear a crack when the bullets slows down before coming down?

Thank you again,
Jan.

Look at Schlieren photographs of supersonic bullets in flight. That conical shock wave around the bullet is the "sonic boom." When it reaches your ears, you'll hear it as a crack or pop. Yes, the bullet and shock wave from the muzzle blast start off together, but the blast wave quickly slows down to the speed of sound over 2-3 feet or less while the bullet may be going twice or more the speed of sound for a considerable distance. And it's continuing to trail that shock wave as long as it's moving faster than Mach 1. The distance between the bullet and the shock wave it's producing and the shock wave from the muzzle blast will continue to increase over distance as the bullet still travels much faster than sound, then begin to catch up only after the bullet drops below the speed of sound. So if you're close to the bullet's passage and a good distance away from the muzzle, you certainly can hear its "crack" before the sound of the shot gets to you. Some Oehler chronographs have even used target frames with microphones to report bullet impact points on a downrange target by triangulation of the arrival times of the bullet's shock wave to the microphones. Rather like how GPS works.