What does the 'pop' noise from gunshots mean exactly?

[DarthVolga 9]

I noticed there's two noises to gunshots. There's the normal sound, and then this weird pop noise you hear along with the original sound sometimes.

What does it mean when you hear that 'popping' noise with gunshots? It sounds like throwing a marble at a hard surface.

[Zera_Grey 28]

the bullet hitting what ever you shot

[suspense 210]

The popping sound appears when a projectile passes you or hits somewhere close to you.

[General Dickbutt 41]

There are 3 different sounds from gunshots.

1. You get hit.

2. The bullet goes right past you

3. The pop sound as you mention, is that they hit something close to you

[MastaOfDisasta 30]

I believe it's the sonic boom from the projectile when it's close enough to you to hear it.

[wolfstriked 143]

Weapons make a different sound depending where you are in relation to the barrel end.When you hear snaps you know bullets are headed your way.;)

Just do this test to see it in action.Go into 3rd person and fire a weapon and as you do move the view around.You will notice it sounds different when watching from behind as opposed to from the front.