On another survival site, they recommended 10,000 22lr rounds, and at least 1,000 rounds for each long rifle and centerfire pistol, reloading supplies not stored in the same place. Also, at least a 2 year supply of food. New MRE's can last 10 years. Traditional canned goods can last 2 years. Vacuum sealed frozen goods can last 2 years, otherwise 1 year. Canned goods can last longer, but they say the vitamens deteriorate after 2 years. Dry goods can last indefinately. If everyone is trying to get this many rounds, then the shortage will last a while.