Tag! You're absurd.

Meet the AA-12, perhaps the most unnecessary weapons ever conceived. Capable of firing 300 nearly-recoilless rounds per minute, and also being A SHOTGUN, it has the added bonus of being banned from combat by the Geneva Convention - which makes it all the more fun to use.

That particular pleasure aside, the main purpose of the AA-12 is for sweet games of tag. Usually, games of tag are limited by the slow firing rate. The AA-12 opens a whole new world of tag-tagback chains, as well as multiple chances for successfully tagging a new "it" despite having missed.

Of course, the anti-recoil feature of the AA-12 renders it useless for use in inertial dampeners, another common application of shotguns (and arguably the one most relevant to space travel). More on that particular technology is forthcoming.