Just a random guess, but maybe it&#x27;s a regulation thing. Like the empire made such military-grade weapons illegal on civilian ships. And having an illegal military-grade autocannon mounted on the side of the ship would attract attention from authorities.<p>Of course this is all my own rationalization: it&#x27;s not like Lucas thought all the intricacies of the Star Wars universe through for their technical accuracy. This is more like literary interpretation, only instead of showing &quot;The Old Man and the Sea&quot; is a metaphor for the tragedy of human existence, we figure out how space ships work!