I guess you don't raise livestock or have chickens/other birds.  "Black" guns (i.e. .223's with large magazines with ergonomic features proven through continuous use by the military) are great firearms for shooting the groups of wildlife that thinks farm animals are a wonderful food source.
"Black" guns of other calibers are great for dangerous game like wild boar, and coincidently, effective for hunting larger game, too.

As for "nut jobs" inflicting their "own brand of evil", not having access to a firearm has been recently shown (and in the past) to not make much of an impact.  The most deadly school massacre was not done with a firearm, as well as the most deadly nightclub massacre.