In Case Of Zombie Hoards Or Low Flying Aircraft

When I was a kid, I used to have dreams about being in a post apocalyptic landscape quite often.  Movies like Omega Man, Mad Max, The Day After, Red Dawn, Battlestar Galactica, Space 1999, Silent Running and many others, painted a gloomy, fatalistic picture of the future, where having a 4 wheel drive weaponized vehicle, a large dog as a pet, a clean water supply, and lots of canned goods stored up would be quite useful to the imagination of a tween & teen age boy.  Never in my wildest dreams did I think I'd ever get a XM214 Automatic Gun (GE Minigun) mounted in the back of a dually pickup.  The number of zombies it could immobilize...  killer cyborgs it could disassemble... or small aircraft it could shoot down... would be formidable.  

Of course, keeping the ammunition supply maintained would be difficult... but if there was an abandoned military base of national guard armory nearby.... the possibilities could be endless!