Corrected entry: When the stormtroopers enter the docking port where the Millenium Falcon is, they start firing. Despite the fact that there are 5 or 6 of them, not only can't they hit Han but there is no damage whatsoever to the Millenium Falcon. But Han, who only has a single gun, manages to destroy half the port.
Xofer
25th Sep 2004
Correction: The stormtroopers are trying to take out Han, since they know they won't be able to disable an entire ship with a small rifle, but Han is sheltered by the legs of the Falcon. Also, Han isn't shooting alone; Chewie is in the ship firing the small gun that comes out of the bottom of the Falcon (which "manages to destroy half the port").
Xofer