DustyGMT asked:
How much is enough?
I knew my income was going to decline precipitously in retirement. Thus, I bought the components that - based on prior use - I believed necessary to load all the ammunition I would need for the rest of my life. The quantity was surprisingly small.
I load all of my own ammunition on a single-stage press, so what I have are components that over the course of an extended period of time could be turned into ammunition, but I have very little ammunition (under 1,000 rounds center-fire) on hand at any given time.
If I were preparing for either civil upheaval or a Ruby Ridge-type siege, I would buy MREs, medical supplies, veterinary antibiotics, and a composting toilet, not ammunition.
Do you keep a certain amount and then rotate it out after a certain amount of time and how do you store it?
No, as indicated above, I bought all the components I would need before I retired.
As to storage, please search my user name for discussion of storage. I have the unique (at least nobody has posted anything comparable) experience of having to leave ammunition components and loaded ammunition in various stages of the reloading process when I was stricken by a neurological disease and kept away from reloading for 20+ years. If you invest the time in such a search, you can read about losses associated with various storage methods when they are used long-term.
Based on that experience, no matter how you choose to store your ammunition, you should expect losses of between 2% and 15%. By losses, I mean the case corroding to the point where I was unwilling to shoot it. You may be pleasantly surprised, but plan for the worst and hope for the best.
Do you stockpile brass or steel cased?
All of the cases that I have bought are brass cases.
I own a single box of 7.62x39 ammunition with steel cases that was given to me by a friend when he owned a rifle that could shoot this ammunition. I have never owned a rifle that can shoot that cartridge.