This probably will be shit on, it's a horrible gun, but it does work.
I have a mosin nagant for this purpose, it was under $100 dollars and at the time the ammo for 440rds was $80 dollars in two sealed "spam cans". I will probably acquire a few more mosins for this purpose. they are not sexy, but 7.62x54R will do work and it's cheap. granted the berdan primed is what i speak off. i am aware of the corrision issue. If the gun after getting cleaned properly and sits in a safe FOREVER, and the spam canned stays sealed. throw in some stripper clips, with cheap cloth bandoleers. I can outfit 10 people for about 1500.
These guns are for non-shooters to have a gun(aunts, uncles, grandparents, people who don't believe in guns). most people know how to use a bolt action.
nothing more nothing less, it's not sexy but it's simple, and effective.
If you are a shooter, you should have a backup site, and come prepared with your own toys.