Firing bullets deleats player not bullet

I have a ship that fires a bullet and i want them to be deleted from the game after they are so far away from the ship but when i try to remove them all i can go it to do is remove the ship.

this is the code i am using

if (bullet.position.z < muzzle.position.z + 100){

		Destroy (gameObject);
	}

try this (changed gameObject to bullet.gameObject):

if (bullet.position.z < muzzle.position.z + 100){ Destroy (bullet.gameObject); }