Fella's;
The one place you do not want to store ammunition, powder, and primers, is in your safe! Particularly if that unit is either an RSC or unrated. If the unit's thermal protection capability is exceeded and one round cooks off, everything else then goes also, and in very short order. I've seen the results of that, and it's not pretty, everything in the unit was lost. The interior of the unit becomes an incandescent cloud of extremely high temperature gas.
I use a G.I. double locker I got at a scrap yard. It was very inexpensive & easy to fix, just pounded out a couple of dents. Made a couple of keys for it, adjusted the shelves, and good to go.
I'm a retired locksmith who used to specialize in safes.
900F