I am sure that this topic has been hashed-out plenty in the past but because I am relatively new to the board I would like to ask the question:  I have "several" ammo cans of .223 and 7.62x39 that I would like to get out of my house and into my shed for storage and need to know if it is ok to store ammo for long periods like this in a non-enviromentally controlled place ie: storage shed,  that gets rather warm in the Texas sun.   I can ventilate the area but I am not going to use a fan or AC, is this ok?   thanks for your input,
EX GI

You might be well off to dig a sort of "root cellar" in the shed in order to better stabilize the temperature around the ammunition. Heat is the big ammo destroyer after moisture.

Storing it in the shed as-is will work for a while, but for long term (ie: years) it will begin to degrade the ammos performance.

Anyone who shot that Egyptian 9mm Milsurp that came in back in the early 90s will remember the less than stellar qualities of ammo that has been stored in the heat...

G2

Ex GI.  A storage shed with no climate control is NOT a good place to store ammo.  When I was in Saudi Arabia, there was very little inside or climate controlled storage.  Mostly ISO containers, CONEXes, and what we called K-spans which were little more than metal butler buildings open on both ends.  The 5.56mm ammo we had stored there really took a beating from the heat and sun and the powder eventually started to crystallize making it unusable and even dangerous.  This is not surprising after 6-7 years of heat that sometimes reached 140-160 inside the storage structures.  The best way to store small arms is in the original military packaging in a cool dry place.  Use some 2 x 4 dunnage under the items to keep them off the floor and provide good air circulation around the packing.  The military typically stores small arms in earth covered igloos which stay cool and dry inside year round and there is very little temperature variation.

 For ammo storage, think 3C - clean, cool, and dry.  I like the 'root cellar' idea, if the ground is damp coat the boxes with tar or auto undercoating.  don,t forget a dessicant inside the can..