Watching those A-10 strafing videos I always wondered why can we hear two distinct BrrrrrrP's? The first one is probably the cartridges discharging sound, the second one might be the impacts, or what? Impact sound ought to be a bit more dull, aren't they?
Impacts first and firing sound second is what I always thought. In the videos I've seen the rounds hit closer to the cam than the plane is so their noise reaches it first.
Super sonic rounds produce an overhead "snap" and the gun's report itself. Including the sound of rounds impacting it's actually possible to hear each round three distinct times.
It might be confusing at first but know that filming starts just after a salvo has struck, but right before the "growl" of the cannon has been heard. Then a second salvo strikes (and if you listen carefully you can hear the "cracks" of the rounds breaking the sound barrier before they explode), and soon after the growl of that salvo being fired is heard as well.
And also, that terrifying "growl" sounds like some ancient beast, or dragon roaring as it soars by. Just imagine what that does to the morale of an enemy possibly somewhat superstitious.
The growl of the a-10, its brute design and the potent power of this old school ballistic weapon just makes it one of the baddest and meanest machines ever produced.
