Fortunately for me where i live there is a guy who runs a gun shop. He has told me on several occaions that the reason he has so many guns that "arent for sale" is because they are his stockpile for a shtf scenario. The reason he keeps them is not for him self, he said he would start handing them out to people.
I am like minded to him, i plan on purchasing many more mosin's in the future for the specific purpose of handing them out. Of course i will be test firing them all so i can keep the most accurate one
7.62x54r isnt the most common round down here but i have about 35 rounds of the special russian stuff that i keep stockpiled just in case the zombies have body armor. The way i see it is if the shtf you will encounter some form of bad guys. Assuming you live through that encounter you will probably be able to pilfer their weapons and ammunition. Maybe even their uniforms, if they have any, for easier traveling. You just need enough ammo to get you through that first encounter. However i still believe in stockpiling large amounts of ammo just in case.