Good or Bad? Rounds stored in heat (unheated shed year round)

[bbogue1]

After I have assembled my rounds for 9mm or 38 Special I store them in ammo boxes (50 or 100 rounds per box). I label them with date, primer used, case, powder brand, powder weight, bullet mold description and bullet weight. They are stored in an unheated shed that may reach 130 F in the summer and about 32 in the winter. No problem that I can directly tie to the temp. I heard today that some double base powders (Like Bulseye) will break down in heat. I use Webster 231 as my main powder, I also have Aliant #5 and Hodgdon 700X. My powder is stored in the house. I suspect I should be storing them in the house if this is true. What is your opinion?

[GONRA]

GONRA sez - heat is BAAAD for powder - in the can or in the ammo. Hope it all verks out for ya'll.... Let us know!

[fcvan]

Heat bad, cold not so bad, but even temp is better. I used to have my gear and ammo in a tin shed where summer temps could get pretty warm, but the shed as always in the shade of trees. Winters were cold and snowy. I shot year round there, and did not notice an effect on performance of Unique, Bullseye, 4198, or 4227.

During the summer at the range the ammo stayed in the shade. Now, I have my ammo in the garage mostly, with stable temps between 50 to 65 degrees at one house, colder and hotter at the other house. However, the ammo at the second house is in cabinets which is an insulator against heat, but not so against cold.

Years ago, dad had his ammo and powder in the basement with similar temp swings as my second house. The temp was always stable. He had a 15 lb keg of Unique in a cardboard container from the mid 1970s. That powder was passed along to us boys and it shot just fine. They say store powder cool and dry, heat is not our friend for ammo.

[Plate plinker]

Unless you have taken precautions, who would store ammo or any other valuable gear in a shed for security purposes. These days some miscreant might find your stash and carry it off.

[clum553946]

130 degree temperature is not good for ammo or powder & probably not good for primers as well

[Ozark mike]

Not to mention lube

[Hutch556]

Yeah, for anything long term I would look into storing your ammo somewhere climate controlled. The heat as well as the temp swings over time I can’t see being good for it.

[sutherpride59]

Modern day ammo should be fine but I wouldn’t chance it. Military regs tell you any ammunition container over 120 degrees needs to be cooled by means of cold water wash every 15 minutes or create an artificial shade. I would say it should be fine but no reason to keep the stuff outside unless you just have pallets of it.

[MT Gianni]

Look for an old refrigerator you can put a locking hasp on and keep it at 50 F.

[fredj338]

No way to reallt say how bad storing in unstable temps can be, but it certainly isnt good for the ammo.

[gwpercle]

Cold is no problem ... it's the 130 degree heat .
Heat causes the powder to break down faster .
I store all my powders , primers and loaded ammo inside the climate controlled house with me.
We both love the a/c in summer.
Gary

[John Boy]

A general rule of thumb for ideal storage temperatures is between 55°F and 85°F. According to SAAMI (Sporting Arms and Ammunition Manufacturers' Institute) standards, extreme high temperatures (over 150° F) should be avoided.

[bbogue1]

Great info. Reassures me that I have been ok in keeping powder and primers inside (70 - 80 degrees year-round). Ammo is coming in today. Funny brain fart, I keep my 22LR inside and have for years. My pistol and shotgun have been stored in the shed, Thanks.

[Bird]

I have shot jacketed military and reloaded ammo that has been stored for years in temps that exceeded 160 and as low as 28 deg. Never had a problem with any of it. Lubed bullets may be a different story though.

[megasupermagnum]

A lot of guys store outdoors in garages and sheds without problems. One of the better methods is to find an old refrigerator, and store in that. You don't need to power it up, it simply serves to maintain the temperature better.

[charlie b]

IMHO humidity control is more important than temperature. If you live in a humid climate then I'd invest in some desiccant and good ammo cans. Out here in the desert I just use ammo cans and stash it in the garage.

[Bazoo]

If stored in an ammo can near the ground, it would receive a lot less temperature variation. But if it was stored on an open shelf next to a tin wall, then it wouldn't fare as well. The question isn't if it's bad for ammo but rather, how long before it degrades noticeably.

Glad you decided to bring it in.

I have occasionally stored a small supply of ammo at an alternate location. In a barn, in an ammo can, on the ground, covered with a bit of hay for both concealment and temp regulation. When my house burnt down, I retrieved it, glad I had it. It had been stored that way maybe 5 years and showed no signs of deterioration on the boxes or cartridges, and all fired fine.

[Texas by God]

I've been storing ammo in my insulated metal shop for 15 years so far. As mentioned, old refrigerators are great, but I haven't had any problems from GI ammo cans, nor wooden or cardboard boxes. I have powder and primers that are 50 years old that still work like new and they have just been in a metal filing cabinet for 25 HOT summers and 25 mildish winters. As said above, I think humidity is the biggest trouble for outdoor building stored ammo, mainly corrosion. My little corner of the earth has been this way for me; yours may be different.

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[Divil]

Your ammo may work or malfunction in some way due to that storage, testing it is the only way to know for sure. That said, if it were my ammo, I would not keep it in such an environment.

[carolina sorillo]

A guy I was doing a job for gave me a couple hundred primers and 3/4lb of powder because he and his sons hadn't reloaded in "years". When he handed them to me I asked where he had kept them.
He said, "In the attic."
"How long they been up there?"
"Uhh, 'bout 20yrs."

Ok, powder and primers in an attic in NC! I used to have a thermometer in my attic, on a 97* day the thermometer said it was 120* in the attic. I took it and loaded a few test rounds. All fired, all chrono'ed where they should and the primers all ignited as they should. I burnt the rest of them up in SASS matches with no problems.

That being said, Do I store my reloads and supplies in the attic? Heck NO!! Mine are in an outbuilding with a window unit set on 80*! I don't recommend others store theirs in the attic either. That is a HARSH environment for anything.

CS