a consideration on where and how you store the ammo is a fire. the fire department needs to know if there is live ammo stored in the house, where it is and whether it is in metal containers where it can do the least harm. nobody is going to be in a big hurry to rush into a burning room with 3000 rounds of live ammo on shelves in a closet unprotected.
The only real danger from live ammo in a fire is when the cases
rupture, the escaping gas will blow burning embers around.
Rounds in a fire do not cook off and spray bullets around. This has been proven time and time again, the most recently by MythBusters. In most cases, the bullets never even leave the case mouth - the cases rupture first.
To answer the original question, there is some ammo in my safe, but the rest of it is in two dedicated, locked, ammo cabinets in the same location as the safe. I don't keep ammo in the garage, in my vehicle, in ammo cans under the bench or any such. No criticism of those that do, however.