Think I am going to have to find a different place for my ammo...? Have been putting most of it in the safe but I have run out of room and yes I have a big safe but darn... I do not want to put any in the main closet but I do have my shop which is rather large...? (30'X56')... It is not heated or cooled but is insulated pretty good...?
I wonder if I should buy another safe and put out there and put most of my spare ammo in it...?
Why do you think your ammunition needs to go in a safe? It is generally recommended against storing it inside a metal container anyway in case your house burns down and the container becomes a giant bomb.
Moisture is really the only thing you have to worry about. Just don't pile it up on the ground where moisture can come up from the concrete (assuming that is what your shop floor is). Aside from maybe some slight tarnish, any modern ammunition will do fine on any storage shelf or cabinet. Throw a goldenrod, silica can or other gun safe moisture control item in there if you want to play on the safe side.
I guess if you live in an area that is really humid, then you'd have to compensate for that.
Personally, I have a shtf, keeping this forever storage of loose ammo in smaller plastic ammo cans to prevent pressurized explosions as well as keeping the weight down for transportation. Then I just have a whole lot of boxes just on shelving I built above my safe.