Is It Safe to Carry Ammo in Your Car? | What You Should Know


Is it safe to carry ammo in your car, or do live rounds pose an immediate danger to your health and property? Can the live ammo explode during transit and result in an injury? Knowing the answers can help ease your mind as a gun owner.

It’s safe to carry ammo in your car if you’re a licensed gun owner, keep it in 55°F to 85°F temperatures, cycle new ammo every six months, and avoid direct UV exposure. To protect ammo from extreme heat and cold while abiding by laws, you can put the ammo in the trunk or passenger compartment.

The rest of the article delves deeper into the subject of ferrying ammo safely in your car without compromising its integrity or your safety.

Proper Car Ammo Storage Guidelines

There are four handy rules when handling and storing ammo, and they apply everywhere, including the car.

  • Keep it dry. Moisture can damage your ammo unless you keep it in ammo cans and moisture-absorbing packets inside the car.
  • Keep it cool. Ammo begins to break down at temperatures higher than 150°F (65.5°C), while subzero temperatures change gunpowder and primer characteristics. The swing from extreme hot and cold weather is equally ruinous to ammo.
  • Keep it fresh. You should avoid stockpiling ammo in the car and make sure to cycle out the old ammo every six months. Proper storage and labeling can help you follow the first-in, first-out rule.
  • Keep it away from the sun. It’s advisable to store your ammo away from the sun since the UV rays are an unstoppable destructive force. Long-term exposure to the sun’s UV rays will break down the gunpowder and primer, causing the ammo to deteriorate.

Best Ways To Store Ammunition in a Car in Case of a Fire

Ammo cans are the best way to store ammunition in the car and safeguard it against fire. Surplus U.S. Military ammo cans and other metallic options are solid options.

While ammo cans aren’t fireproof, they will keep the flames from inside the box and keep the rounds from going off. Steel ammo cans keep the rounds from going off in the unfortunate event the vehicle catches on fire.

However, ammo cans won’t insulate the ammo against the ruinous effects of a fire’s high temperatures.

Best Container To Store Ammo in a Car

I recommend getting waterproof and airtight ammo cans that are designed for long-term ammo storage. You can either preload the ammo into magazines and stash them in the cans or store the loose rounds.

Here are the ammo cans that I recommend, available on Amazon. I feel they are some of the best containers for storing ammo in the car out there. They usually come in more than one size, so get the one appropriate for your needs. Either way, they let you carry hundreds of assorted rounds safely.

What About Weather Extremes?

Ideally, it’s best to store your ammo at temperatures of between 55°F (12.7°C) and 85°F (29.4°C) for the best performance.

Modern-day ammo is well-engineered for excellent performance in extreme weather. However, severe weather—hot and cold—poses a grave danger to your ammo.

When bullets are subjected to extreme temperatures, it affects the nitrocellulose in the gunpowder.

In high heat, the nitrocellulose assumes a gaseous form, causing the ammo to start sweating. The gas begins seeping from the cartridges at about 125°F (51.6°C), and the leakage can lead to imbalanced ammo.

Ammo imbalances alter the pressure in your firearm’s chamber, leading to significant firing inaccuracies.

Can You Leave Ammo in a Cold Car?

You can safely leave ammo in a cold car without noticeable damage as modern-day munition is built to withstand extreme conditions. However, exposing your ammo to extreme cold is a terrible idea. Subzero temperatures impact your ammo’s ballistic performance and will lower the accuracy of long-range shots.

You’d quite possibly experience inaccurate shooting in spring if your ammo were exposed to freezing temperatures during winter. When the weather moves from extreme hot to extreme cold, the temperature swings can damage the casings, primers, and other components.

Can You Leave Ammo in a Hot Car?

It’s best not to consistently leave ammo in a hot car because it might compromise the munition’s integrity. The temperature inside your car will never get high enough to cause them to explode unless it exceeds 400°F (204.4°C). Such high temperatures are not going to happen unless a fire breaks out.

A study by the Arizona State University found that the dashboard temperature in a locked vehicle left in the sun reaches between 180°F – 200°F (82.2°C – 93.3°C). Most people store their ammo and spare mags in the dashboard—the hottest part of the car.

The car’s high temperatures damage the ammo and affect its performance since the high heat degrades ammunition components.

On a sweltering summer day, the internal temperature inside a locked car can climb up to a scorching 130°F to 172°F (54.4°C to 77.7°C).

Humidity poses another risk when you leave ammo in the car in the sweltering summer heat. The moisture can seep inside the firearm, and if you’re using cheap ammo and primer, it will cause problems.

Does Heat Damage Ammunition?

Subjecting your ammo to temperatures higher than 125°F (51.6°C) invites trouble since it alters the priming mixture’s chemical properties and the gunpowder. Temperatures above 150°F (65.5°C) will destroy good ammo by causing severe degradation and leading them to misfire.

  • Intense heat will not cause ammo to ignite, but the intense heat causes extensive damage and destroys munition. High heat impacts the priming mixture and the gunpowder in the cartridge.
  • When ammo is subjected to temperatures above 150°F (65.5°C) for a long time, they experience severe degradation, leading to a significant drop in performance. Eventually, the round stops firing altogether.

That’s why it’s inadvisable to keep your box of ammo in the trunk of your car during a hot summer day. The temperature in the trunk car can spike to over 172°F (77.7°C), which is ruinous to your ammo.

Temperature fluctuations are just as ruinous as extremely high and low temperatures. Always store your ammo in gun safes, gun racks, or storage units, anywhere with a dry interior and consistent temperature.

Can Ammo Explode?

Ammo will crackle and pop in extreme heat but will not explode. The nitrocellulose in the gunpowder ignites at temperatures of 320°F – 338°F (160°C – 170°C) while lead will only melt at temperatures above 621°F (327.2°C), and gunpowder ignites at temperatures over 800°F (426.6°C).

The nitrocellulose in the gunpowder ignites at temperatures of 320°F – 338°F (160°C – 170°C) while lead will only melt at temperatures above 621°F (327.2°C), and gunpowder ignites at temperatures over 800°F (426.6°C).

As you know, a live round comprises a cartridge with a brass case, a primer, a propellant, and finally, the bullet. A cartridge will burst if ignited by extreme heat, but it sounds like fireworks going off rather than an explosion. A bullet is an inert piece of lead and will never explode in any amount of heat.

However, a loaded firearm will ‘cook off’ if it catches on fire. The intense heat causes the weapon to fire all the rounds until the magazine empties.

Legality (Can You Legally Carry Ammo in a Car?)

The legality of carrying ammo in a car depends on the gun laws that vary between states. Some states recognize concealed carry licenses while others don’t, making carrying ammo and guns in the vehicle a tricky situation.

Some states allow loaded firearms in the car, while others require the gun to be unloaded and ammo stored separately from the guns.

Pro Tip: When traveling to or through a restricted state, it’s best to carry an unloaded firearm locked in the trunk of the car. The gun and the ammo must be in two separate lockable containers. You should not have ready access to both the ammo and the firearm from inside your vehicle’s passenger cabin.

Law enforcement agencies are divided on whether a loaded magazine amounts to a loaded gun. To avoid legal troubles, it’s best to transport ammo as loose rounds instead of preloading them in clips and magazines.

It’s best to check the gun laws in your state or any state that you’ll be traveling through to avoid getting cited on gun charges.

Final Thoughts

This article touched on a few important points. Among them are:

  • You can transport ammo in your car if you’re able to do it safely. It’s best to store the rounds in lockable ammo cans as they’re more secure and convenient.
  • Storing ammo in a hot car for a long time can ruin its integrity, leading to misfiring rounds or inaccurate shots.
  • The legality of transporting ammo in the car varies from one state to the next, and it’s best to consult the gun laws to avoid legal trouble.

I hope this info has been helpful. Thanks for reading!

Jim James

Hey, I'm Jim and the author of this website. I have always been interested in survival, fishing, camping, and anything in nature. In fact, while growing up I spent more time on the water than on land! I am also a best-selling author and have a degree in History, Anthropology, and Music. I hope you find value in the articles on this website. Feel free to contact me if you have any questions or input!

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