If you are shot in the head at a distance, no, you will not hear it. The Barrett .50 Caliber sniper shoot a .50 Caliber bullet at 2700 feet per second. The speed of sound is 1056 feet per second. this means the bullet is traveling nearly Mach 3, three times faster than the speed of sound. If you are shot from a mile away, and survive, you will hear the shot about 3 seconds after you are hit. Because of this, the Barrett is considered a stealth sniper, because the victim will never know what hit them.