Everything You Need To Know About Storing Ammo & Bullets In A Hot Car

When summer temperatures have you heading for the AC, you may wonder if it’s safe to store bullets in a hot car. If you’re like most people, you probably regularly experience the sweltering heat of reentering a parked vehicle that has been baked in an asphalt parking lot. Data shows that the interior temperature in a parked car can climb as high as 100° F within an hour. With that being said, is it safe to store bullets in a hot car?

The short answer is yes. For bullets to explode in a hot car, temperatures would need to reach over 300° F. So even in the most extreme heat the modern world has ever seen, the chances of your ammo going off due to extreme interior temperatures are none.

That’s good news for anyone who keeps a weapon or ammo in their car, especially for long periods of time. But just how hot do vehicles get anyways?

How Hot Can a Vehicle Get?

The hottest recorded temperature was 134°F on July 10th, 1913 in the notoriously hot Death Valley, California. While this temperature may be unbearable for humans, it’s nowhere close enough to ignite your ammo by itself. Even if you set your ammo outside all day to soak up the sun’s rays, it still won’t gather enough heat to cook off.

Because you’ve probably experienced the scorching heat of a parked car, you might already know that the interior temperatures of a parked vehicle can exceed the exterior temperatures. But why is this?

When you roll up your windows and park your car while you stroll around the grocery store, the air inside your vehicle stagnates. This trapped air continues to absorb the solar radiation that beats down on your car. Unlike the outside air, which can circulate, the interior air in your vehicle will continue to heat up. After a few hours, the internal temperature of your car may reach temperatures in the low 200s (°F). With these levels of temperature, it is important to understand hot car death prevention measures to keep yourself and your family safe.

Even in this “worst-case” scenario, though, this temperature is not enough to set off the ammunition in your vehicle. Sure, you may feel like you’re going to suffocate in this temperature, but your ammo is safe.

At What Temperature Would Bullets Explode?

Believe it or not, it takes quite a bit of heat for bullets to explode in a hot car. This explosion is often referred to as “cooking off.” Cooking off happens when the gunpowder in ammunition discharges. It can also be caused by the ignition of the primers in the ammo. Or, if the casing of the bullet melts, it could also cause cooking off.

To understand how cooking off occurs, it’s important to look at the three different components of ammunition: primer, projectile, and gunpowder.

Each of these components has different temperature requirements for ignition. In general, the lead casing begins to melt at 621° F. Gunpowder will ignite between 801° F and 867° F. However, the primer has the lowest ignition point. Most primers will ignite starting at 320°F.

As you can see, the explosion temperature of the different components of ammunition are way too high to ever be experienced in the inside of a vehicle. But with ammunition, its not the heat you have to worry about, its the humidity.

Bullets stored in a car.

Best Practices for Keeping Bullets in a Car

Although you don’t necessarily need to worry about ammo cooking off in a hot vehicle, there is another factor to be concerned with and that’s moisture.

Moisture is the number one enemy of ammunition and can negatively impact its functionality and performance. Keeping your ammo protected from moisture is crucial, and by storing ammo in your vehicle and not in a climate controlled environment, you take the chance of having your ammo malfunction.

However, if you decide to keep your ammo in your vehicle there are a few safeguards you can put in place to ensure it works properly when you need it.

#1 Use High Quality Ammo

When you use high quality ammo, moisture is less of an issue to be concerned with. This is because most commercially produced ammo is thoroughly sealed. They use high-quality primers and casings to help lock out any moisture or other contaminants that could affect performance.

If you prefer to reload your own ammo, make sure you buy high quality primers. Cheap primers aren’t necessarily sealed and can lead to issues later down the road, especially if you store it anywhere that isn’t climate controlled like your vehicle.

#2 Store Your Bullets in a Cooler – Without Ice

If you’re storing your ammo in your vehicle and are concerned about moisture, a good option is to place it in a sealed cooler. Don’t worry – you don’t need to put ice packs in there. Placing your ammo in a cooler helps protect it in a couple of different ways. First, the cooler seals out environmental moisture. If you close the cooler while your vehicle is still air-conditioned, it will seal in the dry, cold air and keep out the increasingly humid air as your car heats up.

You can also try placing a desiccant in your small storage cooler. There are a wide variety of desiccants that you can choose from. These desiccants are often used in safes as well. Placing a desiccant canister in your small cooler will help to remove any moisture that may seep in over time.

#3 Use an Ammo Crate

Using an ammo crate is a great way, and probably the best way, to store your ammo in your vehicle. Because they are specifically designed to hold ammunition, it works a lot better than trying to keep your ammo organized in a cooler.

Most of them have built in carrying handles which makes transport a bit easier, and depending on which style you prefer they are stackable.

A good example of this is the MTM AC4C Ammo Crate available on Amazon. It includes four O-ring sealed ammo cans for multiple caliber ammo storage and is by far one of the nicest looking crates available.

Its super sturdy and because of its design, is nearly impossible to knock over. It also comes with 4 tie-down spots where you can strap it to your ATV hassle free. And because its stackable, you can store more ammo with less space. Overall the MTM AC4C ammo crate is a great buy and a great way to store ammo in your car worry free.

  • Water-resistant O-ring seal
  • Double padlock tabbed
  • Molded-in stacking ridges
  • Heavy-duty, latching systems
  • Designed to hold up to 15 pounds of ammo

In Conclusion

So, there you have it. You don’t need to worry about your ammo turning into a fireworks display in your vehicle. While the interior temperatures of parked cars can feel unbearable for us humans, it’s not nearly hot enough to ignite your ammunition. I hope you enjoyed this article. Thanks for reading!