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.
i disagree with this, we are a bit off topic, but one can survive by just eating eggs, banana and walnuts, those three element provide everything that your body needs, mineral, vitamins, omega3, 6 in proportion of 6:1(which is very compared to many standard diet in the world with ratio 12:1 or more) and macronutrient in the right proportion
don't get fooled by cholesterol level in the eggs, it is a blatant bullshit, one can eat as many as he want, they are also rich in lecithin, which fight cholesterol very well, it is also known that eggs actually lower the level of ldl and rise hdl
I don't think that bananas will be easily available in the Mad Max-style post-apocalyptic world. Gold would most certainly shine in this scenario. Gold and ammo, the former to buy food, the latter to protect it...