Most people understand the importance of properly storing firearms. However, correctly storing ammunition is just as critical.
Most ammunition manufacturers state that factory ammo has a shelf life of 10 years. In reality, your ammunition’s shelf life may vary between a few months and indefinitely, depending on the storage methods employed.
With the right knowledge and techniques, it is possible to safely store ammunition for decades and still find it in good condition, even after 30, 40, 50 years, or more.
Know Your Ammunition Needs
Just as there is no one-size-fits-all firearm that is ideal for all purposes in the hands of all shooters, there are no universal rules on the amount of ammunition a gun owner should possess or store at any given time. Your needs should determine your tools, and this principle applies to firearms just as well as for ammunition.
Every type of gun owner may have different needs. Estimate how much ammunition you’re likely to shoot in a month, then double this amount. The result is a minimum baseline amount of ammo you should have in storage at any given time.
An occasional shooter with a Glock 19 who shoots, at most, once or twice a month, and rarely more than 50 rounds, may not need much more than 100 rounds of ammunition; two full boxes. It isn’t much, but it may be more than enough for someone who doesn’t use their firearms often.
Hunters may want to have various types of ammunition at their disposal. The more diverse the game they hunt year-round, the more comprehensive the range of calibers and projectile types they should possess.
Gun owners interested in competitive or practical shooting disciplines may need to train as regularly as possible, potentially inflating their monthly round count to the thousands. For them, having access to bulk ammo for the calibers of their choice may well be a necessity.
Whether or not you need more ammunition than this baseline minimum is your prerogative, but having an idea of how many rounds you need has a determining effect on how much storage space you’ll need.
If you own just a few firearms and keep 2-4 boxes of ammunition per caliber, you may not need more than a gun safe or secure gun cabinet to store everything in one place safely.
Reloaders, competition shooters, survivalists, and gun owners who buy ammunition in bulk may have upward of several thousands of rounds per caliber. It is not uncommon for people to have dedicated workshops or gun rooms where some space is dedicated for ammunition storage.
Keep Your Ammunition Dry
By far, the biggest threat to your ammo’s shelf life is moisture. Exposure to humidity and moisture rapidly damages every component. Wet gunpowder may not ignite, primers may fail to detonate when struck, casings and exposed projectiles made of metals like brass or copper may corrode, typically turning into hues of green.
You should store your ammo in a dry environment. In most situations, a cool, dry room in your house that is not exposed to frequent changes in humidity will suffice.
You should never use degraded rounds, particularly if visibly corroded or exhibiting other signs of exposure to moisture, for serious applications such as self-defense.
If the signs of corrosion are minor, you can attempt to dispose of this ammunition by shooting it during a casual plinking session, as long as you remain safe and remain mindful of the dangers of hang-fires.
If the ammunition is heavily corroded and the casings look visibly pitted and battered, or if you simply don’t trust it for whatever reason, treat it as you would any other dud rounds and dispose of it safely.
Disposing of ammunition is a frustrating experience. Ammunition is expensive.
Military surplus .30-caliber and .50-caliber ammunition cans are a popular choice for ammunition storage. However, if you are buying them used, make sure the rubber seals are in good condition, and there are no apparent traces of rust, corrosion, or physical damage like dents or holes.
Also, consider investing in silica gel packs to keep the inside of your ammunition cans and other storage canisters moisture-free. These packs are inexpensive and provide you with peace of mind.
Keep Your Ammunition Cool
Modern ammunition is generally designed to function reliably in most environments, from the coldest tundras to the hottest deserts. However, it is best to store ammunition for long periods in a controlled climate area if possible.
The gunpowder and the primer compound are sensitive to very high heat. Both components rapidly degrade when exposed to temperatures over 150°F.
There are very few places that can reach this temperature, but one of them is the trunk of a car during a hot summer day, like we have here in Las Vegas.
A more dangerous threat to ammunition than temperature is constant changes of temperature. Temperature fluctuations can accelerate the wear on your rounds’ brass components, degrading the brass casings and primers over time. Storing your ammo in the attic, in a shed, or any room without climate control is usually not recommended, especially if you live in an area where the summers are hot.
Very long-term ammunition storage (measured in years rather than months) requires an environment where the ambient temperature remains as close as possible to 65°F. Anywhere between 55°F and 85°F is safe, but 65°F is ideal.
Sunlight emits a certain amount of ultraviolet radiation, known as UV light. The adverse health effects to humans of exposure to UV light are well-known. Sunlight UVA can also degrade ammunition.
After enough time has passed, leaving ammunition exposed to sunlight can result in degradation similar to what happens to a car’s paint job after spending too long under the sun; the brass eventually starts wearing out.
Fortunately, it’s easy to protect ammunition from UV rays; all that is necessary is to store your ammo inside an opaque container, away from sunlight. A closet, a cabinet, or a drawer, is sufficient, but using dedicated ammunition storage containers, like plastic ammo boxes or metal cans, is preferable.
If you don’t intend to keep more than a few hundred rounds each in the various calibers you use, organizing your ammunition is relatively straightforward. As long as you keep all your ammo in one place, you can simply use the labeling of your original factory boxes to tell them apart.
However, if you wish to store large amounts of ammo in many calibers, then the practice of labeling your boxes, cans, and containers becomes an essential part of proper storage.
Whether you use Tupperware boxes, military surplus ammo cans, modern protective cases, or other ammunition canisters, each container should contain only one type of ammunition, clearly labeled with their respective contents. Use adhesive labels and a marker pen to create easily readable labels.
If you use a canister to store factory 9mm ammunition, you can, as an example, write “9mm” on your label, followed by the brand, bullet weight, and projectile type. Labeling such as “9mm, Winchester White Box, 115-grain FMJ” is clear and easy to identify.
For reloaders, your labels should have all the information you consider essential; caliber, bullet weight, projectile type, cartridge overall length (COAL or OAL), powder charge, etc. The exact details are up to you, as long as the labeling is clear and easy to read.
You can also use these containers to store things besides ammunition. For example, you can have dedicated cans containing spare magazines, holsters and holster parts, stripper clips, speedloaders, and other specific gun parts. Reloaders may want to keep boxes for primers, brass, projectiles, etc.
Frequently Asked Questions About Storing Ammo
Can Ammunition Freeze?
Ammunition does not freeze unless there is moisture present in the powder. However, freezing will affect the cartridge casing, causing it to expand or contract. This changes the ballistic characteristics of the round when it leaves your gun.
Will Ammunition Explode in a Fire?
Until the temperature reaches around 250°F, ammunition will not react and technically is safe to fire.
However, as the temperature rises the cartridge case will rupture. The rounds may or may not fire. The velocity of the rounds, if they do fire, will be lower than if they were shot from a gun.
Will Ammunition Fire if It Gets Wet?
Yes, ammunition will still fire if it gets wet. Modern propellent chemical composition and design will permit the round to fire effectively.
If you carefully dry ammunition that has gotten wet but shows no corrosion signs, you can safely store it and use it in the future.
The Take-home Message
Keep your ammunition stored in a cool, dry, dark environment, and each box or canister should be easily labeled for your safety and organization. Check your ammunition every few months and replace the silica gels.
Taking as many steps as possible for proper storage will ensure that your ammunition remains serviceable and performs as expected even several decades after the original date of manufacture.