a few thousand .22's, mostly for barter
a few hundred rounds of centerfire pistol ammo, but you'd better not need even a dozen such, when everyone is carrying an autorifle of some sort, don't you think? A few hundred rounds of centerfire rifle ammo, stashed here and there. If you are being at all successfull, there will be plenty of guns and ammo to pick up from the dead, barter with, etc, and half of them will be .22lr, after a short time. A great many of them will be suppressed, too. Many, many thousands of "kits" for making "cans" sold in the early 1980's, and many hundreds of thousands of "how to" books and videos, on can-making, have been sold, too. It will very quickly become obvious what an advantage a suppressed .22 auto is, if shtf, and everyone will want at least one. It may be "just" a pistol, to allow quiet foraging, sparing him the waste of 308 ammo on small critters, but it will be very desirable.