Which bullet and explosive sound move faster?

The gun had just pressed the trigger, the bullet had “flown” away, and there was a loud bang. When the bullet was flying, it kept crashing into the air, accompanied by a whoosh. Someone said, the speed of the bullet out of the barrel is 900 m / s, the speed of sound propagation in the air is generally 340 m / s. The bullet speed is greater than twice the speed of sound so naturally the bullet moves faster.

Is that really the case? Let’s take a look back: in the process of flying, bullets constantly friction with the air, its speed will be increasingly slow, and the speed of explosions in the air is generally very little change. So which one is moving faster? Let’s see how the race between bullets and explosions unfold?

In the first stage, the distance from the bullet from the barrel to 600 m, the average flying speed of the bullet is about 450 m / s. The bullet moved much faster than the explosion, far ahead of the opponent. At this distance, if the gunshot is heard, the bullet will soon pass you, flying forward.

In the second stage, in the distance from 600 m to 900 m, due to the air resistance, the bullet speed slowed down, the bullet did not move faster than the sound of the explosion. By then the explosion had gradually caught up, the two guys racing almost shoulder to shoulder to the 900 m mark.
In the third stage, from 900 m onwards, the bullets flew more and more slowly, the explosive noise overwhelmed and then overcame the bullet. At the 1200 m mark, the bullet was exhausted and exhausted, and the explosion still moved far ahead. Then, if you hear the gunfire, the bullet has not even come before you!

The result: bullets can only win the championship within 900 m, and the final champion belongs to the bang.