Best Practices for Ammunition Storage

Store your ammo so it fires when you need it

Modern ammunition doesn't have an expiration date. Stored well, it stays reliable for decades. Three things shorten that life, and every rule on this page beats one of them.

Moisture

Corrodes cases and can seep into primers until a round won't fire.

Heat

Slowly breaks down powder and primers, especially when temperatures swing day to night.

The wrong hands

Kids, guests, and thieves. Locked storage keeps your ammo yours.

The short version

If you only do five things, do these.

Keep it inside your living space. Room temperature and steady beats everything else.
Seal it. A gasketed ammo can with a desiccant pack inside.
Lock it. Use a safe, cabinet, or locked container, and store it apart from your guns if kids are ever around.
Label and rotate. Date every box and shoot the oldest first.
Look before you load. Retire anything corroded, dented, or loose.

Good spots, bad spots

Where you keep ammo matters more than what you keep it in. Here's how the usual places around the house stack up.

Best Fine if it stays dry Avoid

1
Attic
Summer heat builds up here fast, and humidity goes along with it. One of the worst spots in the house.
2
Gun safe in a bedroom
Locked, indoors, and at steady room temperature. Put a hygrometer inside and you're set.
3
Interior closet shelf
Dark and stable, away from exterior walls. Use a lockable container if anyone else lives with you.
4
Garage or shed
Hot in summer, cold in winter, damp most of the year, and the easiest place on the property to break into.
5
Vehicle
A parked car can bake well past outdoor temperatures, and it's a common theft target. Drive it home and bring it in.
6
Basement shelf
Works when the basement is dry. Check the humidity first, use sealed cans, and keep them up on a shelf.
7
Basement floor
Concrete pulls moisture from the ground and passes it straight into whatever's sitting on it.
8
By the water heater, furnace, or laundry
Heat and humidity in one spot. Keep ammo away from appliances and from paints, fuels, and solvents.

Pick the right container

A good seal keeps moisture out. A lock keeps people out. They're two different jobs, and most homes need both.

Container	Keeps moisture out?	Lockable?	Best for
Factory box	No. Cardboard soaks up humidity.	No	Short-term storage, keeping caliber and lot info with the ammo
Caliber-specific ammo box	Not sealed	No	Organizing loose or reloaded rounds, range bags
Plastic ammo can	Yes, with an O-ring lid	Most take a padlock	Everyday storage, range trips, lighter loads to carry
Metal ammo can	Yes, with a good rubber gasket	Some take a padlock	Long-term and bulk storage, stacking
Ammo crate	Yes, on sealed models	Most take a padlock	Bulk storage and organizing several calibers in one place
Ammo cabinet	No, add sealed cans inside	Yes	Large quantities that need to be locked up
Gun safe	No, add sealed cans or a dehumidifier	Yes	Securing guns and ammo, with fire protection on rated models

The setup we recommend

Leave ammo in its factory boxes and put the boxes inside a sealed can with a desiccant pack. You get the can's moisture protection and keep the box's caliber, load, and lot number with the rounds. Then store the cans somewhere locked.

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Win the war on humidity

Moisture is the most common reason stored ammo fails. Most homes are fine, but you won't know yours is until you measure it.

Under 50% humidity: where you want stored ammo.
50 to 60%: add desiccant and keep an eye on it.
Over 60%: corrosion risk. Fix the room or seal everything.

Measure it. An inexpensive digital hygrometer in your safe or storage spot tells you the truth.
One desiccant pack per can. Indicator beads change color when they're full. Recharge or replace them following the maker's directions.
Check the seal. A gasket that's cracked, flattened, or hard won't keep air out. Replace it or the can.
Mind the condensation. Bringing a cold can into a warm room makes moisture form inside. Let it warm up before you open it.
Keep oils and solvents away. Penetrating lubricants and cleaners can creep into primers and kill them.

Keep everyone at home safe

If kids, guests, or roommates are ever in your home, how you store ammo is part of how you store your guns.

Lock it up

Ammo goes in a locked safe, cabinet, or container, not a nightstand drawer or an open shelf.

Store it apart

Keeping ammo separate from unloaded firearms adds one more step between curious hands and a loaded gun.

Control the keys

Keys and combinations stay with responsible adults. Change codes if they get out.

Talk about it

Kids should know the basic rule: don't touch, leave the area, tell an adult. Repeat it often.

Some states have their own safe storage laws, especially where minors live in the home. Check the rules where you live.

Label it, rotate it

Write the caliber and purchase date on every can. When new ammo comes in, put it behind what you already have and shoot from the front, the same way a grocery store rotates milk. Nothing sits forgotten for a decade.

Keep your defensive ammo separate from your practice ammo, and label which is which. Otherwise you'll eventually shoot your carry rounds at paper by accident.

Retire a round if you see

Green or white crust on the case or around the primer
A dented, cracked, or split case
A bullet that's loose, crooked, or pushed deeper than the others
A primer that's corroded or sitting high
Anything that got soaked, frozen while wet, or went through a fire

Don't throw bad ammo in the trash. Ask your local range or police department how to dispose of it.

Common questions

How long does ammo last in storage?

There's no expiration date on modern ammunition. Kept cool, dry, and sealed, it can stay reliable for decades. Conditions wear ammo out, not years.

Is the garage really that bad?

For long-term storage, yes. Garages swing hot and cold, collect humidity, and are often the least secure room you have. If it's your only option, use sealed cans with desiccant, keep them off the floor, and lock them.

Can I store ammo in loaded magazines?

Yes. Modern magazine springs handle staying loaded well. Springs wear mostly from loading and unloading, not from sitting compressed. Rotate defensive magazines now and then and keep them somewhere secure.

Does cold weather hurt stored ammo?

Cold on its own isn't a problem. The danger is condensation when cold ammo moves into a warm, humid room, so let cans warm up before you open them.

Can I vacuum seal ammo?

Yes, and it works well for long-term storage. Toss in a small desiccant pack, label the bag, and store it inside a hard container so the bag can't get punctured.

What happens to ammo in a house fire?

Cartridges that ignite outside a gun aren't contained, so the case usually splits and the bullet doesn't travel far or fast. It's still a hazard to firefighters, which is why fire-rated safes help and why some owners let their local fire department know ammo is stored in the home.

Stock up and store it right

Ammo cans, crates, and desiccants to keep every round ready.

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