Canned meat can be stored a few dozen years. But I guess if that was a question, you should better care for the safety and preservation of your ammo...
A balanced diet requires vegetables, cereal grains, fruits & nuts, meat / fish, and other edibles such as oil, sugar and salt. One can't survive by eating meat alone. And regarding the storage of fire-arms and ammo, it is not that difficult. If taken proper precautions while storing, Ammo can be stocked up for many decades.
If you have a source of complete proteins (canned meat or powdered milk), you can literally feed on grass, leaves and roots to make up for the absence of tasty vegetables, fruits and nuts. Sugar is not required, salt can be kept indefinitely long...
You can't have everything