For goodness sake, please PLEASE do not put your silver in a bank box.
I do not want to sound like a conspiracy theorist or a WTSHTF believer, but...
If you are keeping your coins that you find and not selling them off for their silver value, you have faith in your silver and that it will increase in value. THIS IS TRUE. It is true in part because silver and gold is a tangible and finite wealth that will increase the most when the value of the intangible and endlessly printed Dollar (or euro or whatever your local T.P. may be) is revealed as next to nothing.
Your benefit in holding silver and gold is not minute gains from monthly market fluctuations, but in having physical wealth that your foresight and effort have earned you. In short, your silver will grow the most when the bank you have it stored in fails Do not put your silver in an institution that represents the opposite values that your Precious metals reflect.
Values that they reflect, I might add, off of their exceedingly lustrous, shiny, brilliant, and mirror like surfaces.