Firearms need to be cleaned every year, at least. If you stored them clean, but did not apply oil and lubricant, depending on where you live and how it was stored, time will take its toll eventually. If you did apply oil and lubricant, in a year it will dry somewhat and slowly not protect it anymore. Its still something, and in ten years it will keep itself fairly well-maintained, depending on other circunstances. The once-a-year rule is golden because if you skip an entire year, it will -still- be enough that it keeps itself perfect. Gun warehouses have that rule so at least every two years, stored guns are kept crisp clean.