The zombie apocalypse is the only way I run out of ammo! Even then I'll last a long time! If need be I can set a snare and fish pretty good.
I have a old book I got when I was in Boy Scouts called The Outdoorsman's handbook by Clyde Ormond. Learned many outdoor skills I still use from that book.
I have one of those red well pumps, the kind that need to be primed to get water to the surface. Bought it years ago to use as a decoration for my newel post to the stairs. Still have it with my set of fox fire books from the 1970's. I can get with a pipe either out of a well or lake with this.
Nam taught us about bear traps, just dig a few holes around the house, put in a few sharp stick's , cover with twigs and leaves, never know what one is going to catch in these darn things.
Point is what happens when one runs out of Ammo. ? One or two reels of fishing string, high tense placed about the property can do the job of alerting one someone is coming, you will hear the cussing when they trip and fall.
Depending on the strength of the string and the tightness of the wrap, a deer running get one in the neck will go down. As will a humane.
Lots of ideas on survival out there, not a bad idea to check out on indigenous plants that are poison, then if very hungry and the fish are not biting, a load of gun power may being them to the surface to grab. No gun powder throw in Ivory Soap flakes, takes he oxygen out of the water and causes the fish to surface.
All these ideas on how to survive when the Ammo is used up. Must be many more.