I just purchased a new shed for the back yard and there are a few things I want to move out of the house and in to the shed

One of those items is ammo

The temp here fluctuates between 30 and 115, humidity is in the upper single digits to 50% at times

looking for a container that can be 'hermetically' sealed for want of a better term

any ideas form the collective?

US Military ammo cans is what I use

Yes, USGI cans. The Tucson heat won’t do it any favors. At least store it low, on the floor.

I have all my ammo stored in these.
https://www.tractorsupply.com/...-steel-underbody-box
They seal up super tight. You’ll need to seal up the mounting holes on the back.
I have the ammo I have for long term storage in ammo cans inside of these. Ammo I plan to use sometime soon is just in factory boxes in these. Anytime I get desiccant packs in a package I toss them in.

May try putting a solar powered attic fan on the shed to keep temps down a little bit.

I use military ammo cans too and like Black, throw a couple of desiccant packs in each. I'm fortunate enough to have climate controlled closet space too.

What “little” ammo I have is stored in GI cans and stored in safes inside the house. Each safe has multiple rechargeable desiccant packs inside.

Not sure Id want to store ammo outside, even in your area.

I run a dehumidifier, 24 x 7.

I get from 4 to 8 gallons a weeK.

You guys suggesting dehumidifiers and desiccant packs, did you notice that the OP is in Tucson, AZ? There's more moisture on the moon.

^^^^sure did.

The temp swings will "work harden" the brass over time. Use totally watertight containers, but it would be best to bury them or find a location that does not fluctuate so much.

quote:

Originally posted by nhtagmember:
The temp here fluctuates between 30 and 115, ...

I don't think I'd care to subject my ammo to such temperature extremes/fluctuations over time.

quote:

Originally posted by sigcrazy7:
You guys suggesting dehumidifiers and desiccant packs, did you notice that the OP is in Tucson, AZ? There's more moisture on the moon.

Nonetheless: Warm air holds more moisture than cold. If the cans are opened during very warm periods, there may be condensation in the cans during very cold temperatures.

I'd personally find other things to move into the shed and keep the ammo in the house.

Leaving ammo in shed, that's separate from your home, that has zero insulation or, temp moderation leaves yourself open to problems. If you have to move them out, probably best to find some surplus Pelican cases, as in the big ones where you can seal and secure.

quote:

Originally posted by Nismo:
I'd personally find other things to move into the shed and keep the ammo in the house.

Agreed . There's all sorts of places you can find to stash ammo inside . It does NOT need to be kept in a safe .

Just about everybody I know here in Arizona stores their ammo either in a shed in the yard or in the garage. Don't know anybody who's had problems because of that.

Ammo could be a problem if it gets soaking wet. It is pretty durable as a rule. The biggest concern I would have would be security.

quote:

The temp swings will "work harden" the brass over time.

really. show me some research that shows that and its effect on ammo.
"temp moderation"
There no temp moderation from a pelican case! or any other container.

In any case Surplus ammo that you know has decades of bad storage goes bang.
Me personally I personally store ammo in an environment with -20F to 120F (0-100 RH) and over more than 5 decades have never had a round with a problem. This is simply a non problem. As for a container Ammo cans work great, pelican cases work great. But if you have any amount of ammo then you are looking at serious qty of containers. Using the very high quality stuff suggested by black92lx I'd need to win the lottery to house the stuff in those.
I stack mine on steel racks in its original box or case fwiw and that hasn't had any issues.

I was a gunners mate in the USCG. We had to take and record the temperature daily. For several reasons. One was to identify ammo that had been subjected to temps over 100°f.

The clock starts at 100° and at ten degree increments, at each level the ammo was allowed to be there for “x” amount of hours before the ammo was reclassified.

This clock helped decide when that ammo was no longer allowed to be issued for general use(combat) and the ammo would be classified to another level (think training)

I’m sorry I don’t remember the exact amount of times, but it did affect ammo I had aboard one ship when we went to the Caribbean. The ready ammo magazines were not air conditioned and that ammo was sent back to a ammo facility upon our return to the US…so maybe 100 hours at 110°f…

If there were so many hours above 100° eventually it would be condemned and destroyed.

I wouldn’t store ammo outside where you are OP.

I live in central TX and it gets over 100° annually, I store my ammo inside the main bedroom closet in regular USGI ammo cans. We keep the house around 74° in the summer…

Heat is what makes powder degrade. And the more heat, the quicker it will go bad.

You can experiment with this by placing a teaspoon of powder in an ammo can and leave it outside in the shade this summer and check it weekly..the powder will begin changing color and the powder will smell different as it degrades.

You did not mention humidity. Is that not a factor?

How did we store ammo for 20 years in Iraq and Afghanistan?