Because the bullet bounces around inside the skull and makes a mess in there.

The bullet fell out with them and bounced on the rug.

One of Nick's bodyguards was flattened by the barrage; the bullets bounced his dead form all over the sidewalk.

That's why bullets will often bounce right off a curved windshield.

The bullet whined and bounced in the small room, luckily missing everyone.

With the Magnum rounds, the bullets would bounce around a lot off the bulkheads.

Lois grabs the machine gun and returns fire, only to have the bullets bounce harmlessly off of the armored car.

And he's got a friend with him, some new ace, looks normal but bullets bounce right off him.

Soldiers were firing at him; the bullets were bouncing off the metal hide of the mole.

The bullet bounced the man's head off the stone, killing him instantly.