How to Store Ammo: What SAAMI and the Ammo Makers Say

Short answer: How to store ammo, according to SAAMI and the ammunition makers: keep it in the factory box, somewhere cool and dry, out of direct sunlight, away from water and solvents, and never above 150°F. Lock it up, out of the reach of children. Federal safe-storage guidance adds one more step: keep it locked in a separate place from the firearms.

SAAMI — the Sporting Arms and Ammunition Manufacturers' Institute — publishes the industry's storage leaflet, and most ammo makers point back to it. Speer's FAQ does exactly that. This guide follows those documents and stays out of reloading. If you're choosing the locked box first, our gun safes page covers the options.

How to store ammo: the factory box is the first container

SAAMI's first instruction is the simplest: "Ammunition should be stored in the factory carton or package." The reason is practical. The label on that box says which cartridge is inside, which helps make sure it goes into the gun it was made for.

SAAMI adds that ammunition is packed in cartons and cases specified by the US Department of Transportation, and that "unapproved packaging should never be substituted." That language is aimed at shipping and storage in commerce. At home, the takeaway is the same: the original box is part of the product.

Speer's FAQ, asked about long-term storage, gives the short version: "cool and dry conditions in original packaging," and refers readers to SAAMI's guidelines for the rest.

Plenty of people put those boxes inside a sealed ammo can. Nothing in SAAMI's leaflet forbids that. Just keep the box inside the can, so the label stays with the rounds.

Where to store ammo: cool, dry, and nowhere near 150°F

Federal Ammunition's FAQ says to store ammunition "in a cool, dry place, protected from direct exposure to sunlight." SAAMI gives the hard limit: "Extreme high temperatures (over 150° F) however, should be avoided."

Most rooms in a house never get close. Some places do. SAAMI calls out one by name: the passenger compartment of a closed car in the sun "often develops an extreme high temperature and is thus not a desirable spot to leave ammunition." It recommends taking firearms and ammunition out of the vehicle after a trip.

The car got hot. The ammo got moved. Case closed.

A short list of where ammunition fits the brief, and where it doesn't:

• Good: a closet or cabinet inside the heated and cooled part of the house, with a lock
• Think twice: an attic, a detached shed or a garage that bakes in summer — measure before you trust it
• Avoid: a closed car in the sun, per SAAMI
• Floors that get damp: SAAMI advises stacking cartons on pallets when stock sits on basement or warehouse floors subject to moisture

The Closet, as usual, wins by default. It's inside the living space, it's dark and it holds a steady temperature. It just needs a lock.

Water, solvents and oil: what ruins ammo in storage

SAAMI is specific about what not to expose ammunition to: water, or "any organic solvent, paint thinner, petroleum product, ammonia, etc." It explains why: these can penetrate a loaded round and reach the powder or primer. The result can be misfires or squib shots, where a bullet lodges in the barrel and the next shot becomes dangerous.

That puts a few habits in a new light:

• Don't store ammunition on the same shelf as cleaning solvent or oil.
• Don't spray lubricant near open boxes.
• Don't keep ammo where a leak or flood could reach it.

Humidity is the gentler version of the same problem. SAAMI says ammunition in factory packaging, subject to "ordinary variations of temperature and humidity ranging from tropic to Arctic conditions," can be expected to perform satisfactorily over extended periods. So you don't need a laboratory. You need to avoid soaking it. If the ammo shares a gun safe, the same 40–50% range from our ideal gun safe humidity guide suits both.

Can you store ammo in a gun safe? Yes, with one catch

Physically, there's nothing wrong with it. SAAMI says the ideal home storage for ammunition is "a locked closet or cabinet out of the reach of children and uninformed or incompetent persons." A locked gun safe meets that description.

A shelf in the gun safe, a separate locked cabinet, a lockable steel can — any of them works if it's locked and the conditions above are met.

The catch is fire, and it gets its own section below. First, the question that matters more.

Can you store guns and ammo together? What federal guidance says

This section is about children and firearm access, so it's plain.

Federal guidance recommends keeping them apart. The U.S. Attorney's Office for the District of Vermont, in its Department of Justice handout "Safe Storage of Firearms," says to unload each firearm before storing it and to "keep ammunition locked in a secure location away from the firearm." The Department of Justice's Safe Storage Fact Sheet says keeping firearms locked, unloaded and stored away from ammunition can significantly reduce the risk that children and teens use a firearm to hurt themselves or others.

The same Vermont handout says to keep the keys and combinations to gun storage and to ammunition storage in separate locations, out of the reach of children. The National Park Service's guidance for museum collections says the same thing in four words: "Store guns and ammunition separately."

In practice, that can mean:

• firearms unloaded in a locked gun safe
• ammunition in a separate locked container, cabinet or room
• keys and codes for each kept apart and out of children's reach

State law on storing guns and ammo varies

Storage requirements are set by state law, and they differ from state to state. We don't summarize them and this is not legal advice. Massachusetts publishes its firearm statutes, including its storage section, on mass.gov. California's Department of Justice publishes its firearm rules through the Bureau of Firearms. For any other state, go to that state's official government site or ask the state agency directly.

Ammo in a house fire: what SAAMI says actually happens

SAAMI's leaflet spends a lot of space on fire, because firefighters asked. Its findings, stated plainly:

• "Stocks of small arms ammunition will NOT mass explode." If one round fires, adjacent rounds do not explode with it.
• Ammunition that ignites outside a firearm's chamber "discharges inefficiently." Bullets rarely travel far; small fragments of case and primer can fly short distances, usually not over 50 feet.
• Tests by SAAMI members show the fragments do not have enough energy to penetrate firefighters' protective gear.
• SAAMI says it has no verified report of a firefighter hurt by flying bullets or shot in fires involving a home supply of ammunition.

SAAMI also produced a video for the fire service on what happens when ammunition burns, listed on its publications page.

After any fire, SAAMI's instruction is clear. Ammunition that has been in a structural fire, scorched, wetted or exposed to flood water should be scrapped, not used or sold.

Ammo shelf life and getting rid of old rounds

Federal's FAQ answers the shelf-life question directly: if stored properly, loaded ammunition and reloading components "have a 10-year shelf life." SAAMI's leaflet doesn't give a number. It says ammunition in factory packaging can be expected to perform satisfactorily over extended periods, under ordinary home conditions.

One maker gives a number. The standards body declines to. Both say the same thing about the conditions.

When ammunition has to go, SAAMI says:

• Never bury it or dump it in a waterway. It can be found years later, still live, by children or someone who doesn't know what it is.
• Return it to the manufacturer in most cases, after getting written permission first.
• If you don't know the maker, SAAMI says to contact SAAMI.

Here's the catch: a fire-rated gun safe isn't rated for ammo

A fire rating protects what it was tested for. UL explains that a UL fire rating has a class, which is the maximum interior temperature reached during testing, and a time rating. UL's standard says Class 350 ratings are intended to protect paper records.

Read that next to SAAMI's limit. A Class 350 test allows the inside of the safe to reach 350°F. SAAMI says to avoid temperatures over 150°F. A safe can do its job for your papers and still let the ammo inside get far hotter than SAAMI's ceiling.

(The fire label on the door was written for the deed to the house. Nobody asked the cartridges.)

That doesn't make the gun safe a bad place for ammunition. It still adds a lock, and SAAMI's own fire findings say a stock of ammunition won't mass explode. It means the fire rating on the door shouldn't be counted as protection for the ammo. After a fire, SAAMI says scrap it either way. For what fire ratings on gun safes do cover, see our guide are gun safes fireproof.

Skip it if: when you don't need special ammo storage

• You keep a few boxes in a locked, climate-controlled room. That already matches SAAMI's guidance. No extra gear needed.
• You're shopping for a "humidity-proof" ammo vault. SAAMI says factory-packed ammo handles ordinary household humidity. Keep it dry and off damp floors; that's the job.
• You're buying a bigger fire rating for the ammo. As above, a higher fire class is aimed at paper and media, not cartridges.
• You're about to repack everything into unlabeled jars. Don't. SAAMI wants the factory box, for the label.

Put the boxes back in their factory cartons, move them out of the car and off the damp floor, and give them a lock of their own. Then put that key somewhere different from the gun safe key, out of children's reach. For the rest of the setup, see our gun storage ideas.