I keep a minimum of 250 rounds of self defense ammo per side-arm and HD shotgun, 500 rounds per firearm per caliber (i.e.: 2 9mms= 1000 rounds) of standard FMJ, 1000 rounds of my reloads per firearm per caliber for general practice and hunting.
I also store enough raw metal(s) for casting, over-the-counter bullets, powder, primers, and cases for all to last 5 years just in case the SHTF.
All ammo, powder, and primers along with any chemicals are stored separately according to component in separate safes in different locations for obvious safety reasons. Everything is stored and kept in accordance to local, state and federal regulation.