Does Ammo Go Bad?

Does Ammo Go Bad?

June 30, 2022 By Posted in Blogs

Does ammo go bad? It’s a common question and one that is fairly simple to answer. Generally, ammo does not go bad; however, some storage conditions can cause ammo to fail, and there are some downsides to long term storage of ammo, including:

·      Corrosion. Brass is a reactive metal. If exposed to moisture or high humidity, it can corrode, and the corrosion can impact the powder which, in turn, may cause the round to behave differently. Corrosive ammunition could perform poorly, fire with lower velocity, or it may not fire at all.

·      Decreased Shelf Life. Ammo that is not stored properly can fail to fire or not fire as expected. While ammo generally does not have a shelf life, it can go bad. Modern ammo is generally manufactured for longer storage life.

What is the Shelf Life of Ammo?

The shelf life of ammo is complex. You can think of ammo as having a “best if used by” date rather than an expiration date. If stored properly, ammo can and will last decades. In general terms, as every ammo and brand of ammo is different, you can expect rounds to last about a decade if you store them properly.

The factors that go into the lifespan of ammo include:

Environmental Conditions. Humidity, extreme heat, and excess moisture can damage your rounds and cause a variation in how it fires or if it will fire at all. Bad ammunition can be very dangerous.

Storage. How the cartridges are stored is also important. Not only will storing your rounds properly help you to keep them organized, but it also adds greater safety to having ammo in the house. The biggest reason that proper storage helps preserve the lifecycle of your ammo is that it allows you to control the environment that your rounds are exposed to every day.

What Can Happen When Using Expired Ammo?

Usually, the round fires like normal, but not always. With brass rounds, you may see the round begin to degrade. Modern ammunition with brass casings is bright and shiny. As time passes and the rounds are exposed to moisture, the brass fades to a dull color. At this point, the round remains safe to shoot. As more time passes, the brass may oxidize further, and green corrosion may show. Corrosion weakens the casing and, when fired, the pressure inside the round can cause eruptions through the casing.

In extreme cases, the corrosive damage can be severe when focused on the priming compound and the top of the casing. When there is damage to the primer cap, the bullet should be safely discarded and not fired. Too much damage to the primer can cause the bullet to not fire at all, to fire at slower speeds, or to fire only the primer but not the powder.

A bullet that fires slowly and lodges in the barrel is called a squib. Squibs are dangerous. Sometimes, if the powder has lost its potency the round may fire at lower speeds and lodge in the barrel (squib round.) If that happens, the next round can cause significant damage to the barrel and the barrel may explode, injuring the shooter and potentially ruining the firearm.

If the round shows signs of corrosion, the best course of action is to safely dispose of the round. 

Proper Ammo Storage

When you employ an ammo storage system, whether that’s a basic ammo box or something more elaborate, it must address the following factors:

Humidity. Not only can humidity form inside the round, but it can also cause a chemical reaction which leads to oxidation and corrosion.
Temperature. Temperature fluctuations, such as seasonal highs and lows can impact the quality of the primer and powder. Temperature can impact humidity, too. A good storage solution for ammo means that the rounds stay at room temperature and are protected from extreme temperature ranges, direct sunlight, and moisture.

Safety. Just like with guns, you should have a storage solution that locks your ammo away from easy access.


1. Avoid extreme temperature swings. Keeping ammo at room temperature between 55°F-80°F is a good goal.

2.Store ammo in an environmentally controlled location. Avoid storing ammo in the garage or locations where temperature and humidity are active.

3.Keep your storage containers in a dry place. Toss a few moisture absorbers, like silica gel packets, into your ammo storage box. Be sure to change the moisture-absorbing packs on a regular basis.

4.Keep ammo in its original box and store it in an ammo box. Ultimately, an ammo box with a silica gel packet will help to keep humidity outside and reduce corrosion.

5.Store ammo in a dark place. If you keep ammo in the light, it can heat up. A darker location helps to control storage temperatures.


A few things to avoid when storing ammo includes:

1.Extreme Temperatures. Temperatures over 100 °F and below 40 °F can affect the powder or primer quality. Cycling between hot and cold can cause the metal components of your rounds to expand and contract and ultimately loosen connections and fittings. When that happens, air can tarnish the powder and primer and the rounds may not work as designed.

2.High Humidity. Humidity can cause metal corrosion and chemical reactions. The moisture that stored rounds experience in highly humid situations can damage the primer and the powder. Humidity may appear inside the round and on the outside of the casing.

3.Casually Storing Ammo. Never leave ammo in your vehicle for more than a day. Never store ammo in a garage or outbuilding where there is no temperature control. Both a vehicle and a garage can become very hot or cold depending on the season. Ammo stored casually can be found by kids or may become damaged by pests. Rodent urine on brass rounds will quickly cause corrosion.

4.Sunlight. When you store shells in direct sunlight, the fluctuating temperatures can damage even modern ammunition. Sunlight transfers heat energy to objects and heat energy is one form of energy that you want to avoid when it comes to storing shells.

Berry’s Storage Solutions


Ammo cans are a good place to start for the storage of rounds. Berry’s Ammo Cans are offered in 20, 30, and 40 caliber sizes and the new Berry’s Tri-Can can hold multiple calibers in one can. The benefit of an ammo can is that it helps to keep your ammo in one spot and its compact size can fit in a gun-safe or secure location without taking up a lot of room.

Berry’s ammo cans come with a rubber gasket that helps seal the unit against air exchange and moisture. They are also made to be stackable, helping with space management. An ammo can is a good investment for times when you want to store larger amounts of rounds. For smaller rounds and traveling with rounds, an ammo box may be a better solution.


Ammo boxes offer another approach to storing rounds. Small ammo boxes may hold 10 rounds whereas larger ammo boxes may hold upwards of 100 rounds. If you are looking for a secure way to carry extra rounds for concealed carry, an ammo box may be a good choice. Ammo boxes are sized by caliber, but there are options for holding many shells.

A utility ammo box is a good option when you need to store larger amounts of ammo. Ammo boxes are also a good solution when you need to transport ammo from home to the shooting range or target field, or on a hunting trip. They allow you to carry a specified amount of ammo without hauling all of your ammo along with you.

If you are like us, and you have many guns, ammo boxes allow you to sort and store ammo, so you can visually see how much ammo you have and in what calibers. Even old ammunition will store better in an ammo box. Ammo boxes are also available for shotgun shells.

Berry’s offers a range of ammunition storage solutions that address the care requirements of storing ammo. Shop our collection of ammo cans and ammo boxes available in different capacities and for various calibers or rounds. While you’re at it, check out our selection of bullets and “round” out your ammo box.