Powder storage temps

[Michael]

On the other post the discussion was on powder storage methods, i.e. wooden cabinet, old fridge/freezer, bottom of the lake, etc., started me thinking...(oh no here he goes again...)

What about storage temps? Cool and dry is the universal best answer for most things but not everyone has that option most of the time. In S. AZ, NM, TX, etc. cool can be a few fleeting months followed by 6-8 months of hot or hotter. Up north, cool is the exact opposite with 6-8 months of if it's left outside it's going to get frosty or freeze, sometimes even in a garage.

We all know hot is not good, the hotter it gets and in addition to time, shelf/storage life diminishes. So what about cooler temps, even sub freezing, how cold is too cold and for how long? Not only just smokeless, but BP and primers as well.

 

[RicinYakima]

We all know hot is not good, the hotter it gets and in addition to time, shelf/storage life diminishes. So what about cooler temps, even sub freezing, how cold is too cold and for how long? Not only just smokeless, but BP and primers as well.

I have lived in this house for 47 years. Winters commonly below zero and summers above 100*. However daily temps very 40 to 50 degrees. Humidity may be between 10% and 25% during the day. Powder and primers stored in wooded boxes on a concrete floor, so slow moving temperatures. Never had an issue.

 

[Dusty Bannister]

I also agree that stable temps are favorable even if a little warm or a little cold. Humidity control might simply be a zip lock bag to enclose containers of powder and some desiccant bags.

 

[Ian]

I have abused powder and primers terribly with heat and humidity in the past, never had an issue either.

 

[fiver]

i'm in pretty good shape here.
pretty easy to maintain 60-65 and humidity in the 35% range.
of course there's some excursions from time to time but nothing like 90F or 90%.

 

[Winelover]

I wanted the majority of my powder out of the house. Was in the process of building a second detached garage so I sunk a 55-gallon plastic barrel. Temperature stays at constant 55 degrees.

 

[Rally]

Wine lover,
Great idea, but it doesn’t work here. Our frost line is 46” and the freeze thaw cycle here moves slab on grade structures. Lots of folks tried metal and plastic barrels here, only to find they crack or rust out. Now some folks have been having good luck pouring cement inside two inch foam walls, which compress as the ground moves/ compresses.
I have a friend that buys estates of guns/ reloading supplies. I’ve used a bunch of powder I bought from him with exterior rust on the outside.of the cans with good results. Most of it came from being stored in outbuildings without heat. If there is any rust inside I won’t use it. I’ve found more corroded primers in factory packaging than bad powder. Any water stains on primer packaging they get thrown out. I’ve used primers that the packaging was sun bleached and they worked fine. We don’t get much over 90 here, so can’t comment much on extreme heat storage. Keeping things dry here is more of a worry to me, lots of surface water here.

 

[JonB]

I agree with Rally, as we are in same State.
My biggest storage foe (in unheated buildings) is the freeze-thaw and humidity, frost/condensation cycles (I'm not sure I worded that correctly? but some of you know what the I mean, LOL.)

 

[Glaciers]

Well I have all my powder just in shelves from about 4 feet down to the floor. Keep 4 and 8’s on the floor. Floor is wood, room as in any building you plan to heat is well insulated, it is Alaska after all. Insulation is cheap compared to fuel oil. Winter temperatures 50 to 60 degrees. Summer might get to 60. Never allow a freezing at any time.
I have some powder in Southern Oregon that is in unheated garage but as it’s might get to 30 degrees in winter for a day or two so no problem there. But Summer gets hot, sometimes 115, commonly over 100 degrees. I have a small fridge that the powder is in turned on low. No too concerned. I think moisture would be the biggest problem for long term storage.
Some of my Alaska powder is 4831 from WW2. Still good.

 

[Matt_G]

I keep everything in the basement.
When its -10 outside, its 67 in the basement.
When its 100 outside, its 72 in the basement.

 

[RBHarter]

GI storage is quoted as -40 to +140° .
Bunker temps with -10° for a month rarely dip below 15° . 105-110° lasting most of 6 weeks rarely break 90° .
Most of the year has a stable temp of 30-75°, annual average temp is about 55° .

Loaded ammo holds 60 yr , reclaimed/reset flaked TNT/RDX lasts at least 60 yr , misc canned propellants over 70 yr .

 

[dale2242]

I am shooting H4831 that I am pretty sure is WW2 vintage.
It is as good as new.

 

[RicinYakima]

I have the DuPont history book they published for their 150 anniversary. After being pushed out of WW1 as the major powder producer (Hercules) they entered the 1939 contract at "cost plus 10%". So, they made the most perfect powder they could without regard to cost. Which is why 4831 and 4895 powders have held up so well for 75 years.