Or for as long as the bullets last and the trucks will have stopped rolling a loooong time ago, but it sure will provide you with a nice long buffer to figure things out in the meantime.
One bullet can last you very long time. I have been eating the same deer as a single source of meat since January and I'm not even half there yet.
Add some means of meat conservation and you could easily last a year on less than 10 bullets. I don't have a prepper ways to conservate meat though (sausage drying, vacuum sealing and solar panels powered freezer probably wouldn't work).
Big deer or boar can weight over 300 pounds. About 2/3 is edible. Let's say one pound of lean meat is 800 kcal. And daily intake is 2000 kcal. Assuming eating only meat that's 80 days of calories.
