My primary go-to is a 12 gauge Mossberg 500 pump shotgun, because shooting a duck with an AR-15 leaves very little but feathers, and an AK will turn a rabbit to goo. A pump shotgun will kill both with ease and still leave them edible. Load it with buckshot and it will also take out feral humans if need be. If I see a deer or a feral hog, I drop in a slug. An M500 is a very tough, reliable weapon, and 12ga is the most common centerfire ammo in the USA. A shotgun is the one weapon who’s ballistic charactaristics change dramatically just by switching ammo.