Car Gun Storage In Hot Weather

store a gun in a car

What Do I Need For Car Gun Storage In Hot Weather?


Not everyone can carry at their place of work, which is why a lot of people use car gun storage during the day. Some wonder whether it is safe to do so during the hot summer months, as temperatures in a parked car can climb to well over 100 degrees Fahrenheit.


The truth is that a hot car is not the dangerous place for firearms that some believe it is, at least in most cases. Very little is actually needed to ensure that the oppressive summer heat damages your firearm or ammunition. Obviously, it would be better if more employers allowed concealed carry at work, but that sadly isn’t an option in many workplaces.


Heat Is No Issue In Car Gun Storage…Mostly


Car gun storage harming a firearm due to the heat is a gun myth that just won’t entirely die. Nothing from a hot day will harm a gun. Bullets, on the other hand…is another matter.


Cars easily get hot enough during a summer day to pose lethal danger to children or pets left inside, but bullets? Not so much. Only in very rare circumstances could car temperatures reach more than 150 degrees; somewhere between 120 and 140 degrees is about as hot it will get in there.


It depends on who you talk to, but in order for bullets to discharge, they have to be exposed to temperatures well in excess of 300 degrees. In an episode of “Mythbusters,” they put a loaded pistol in an oven, which didn’t discharge until the oven reached temperatures greater than 400 degrees. Granted, there are a huge number of variables involved – what type of casing, cartridge, primer and powder are being used, etc – but suffice to say a bullet isn’t likely going to be set off unless you basically throw it into a fire.


On a side note, don’t ever do that.


However, there is some evidence to suggest that temperatures around 150 degrees – easily reachable in a car’s trunk in the height of summer – can damage propellants. Guns and Ammo quoted the managing director of the Sporting Arms and Ammunition Manufacturer’s Institute (or SAAMI) as saying normal temperatures are fine, but adverse reactions can occur at around 150 degrees that can eventually lead to failures to ignite.


In other words, leaving a pistol and ammunition in a hot car is safe, but it can damage ammunition if done for too long.


It’s The Humidity That Gets You


Just like heat in the Southern states, it’s the humidity that can do the real damage. It’s not that a bit of moisture will set a cartridge off, that’s not it. In point of fact, it’s the opposite problem; humidity will prevent ammunition from discharging when you want it to.


This is the one area in which storing a gun in a hot car may do some damage. The gun itself won’t be harmed by the heat, but the humidity may cause rust to form on non-stainless steel pistols. However, a weekly cleaning, lubrication and treatment with firearm-specific rust prevention will ward off the effects of oxidation.


As far as concealed carry ammunition is concerned, modern cartridges are crimped to be virtually air and watertight. A large amount of moisture is not going to get into ammunition. However, a small amount can over time – and it doesn’t take much moisture to deactivate the primer.


Exposure to humid air can allow trace amounts of moisture to get into the primer, one of the areas where the seal on a cartridge can be weakest. If moisture gets in, the priming compound will get wet and as we know, wet things don’t burn very well – and burning the primer and propellant is kind of necessary for a gunshot to happen.


It isn’t so much that one exposure to moisture is going to deactivate primers. They can be dropped in water and work perfectly well after a bit of drying. If stored wet, however, moisture can find a way in.


Therefore, repeat exposure to high humidity or other sources of moisture is to be avoided.


Get A Car Gun Safe And Cycle Out Exposed Ammunition


So, if one is going to store their gun in their car during the high heat of the year, a car gun safe is a wise move. Temperatures may still fluctuate, but humidity will be more controlled.


Car safes can be large or they can be small – many popular models are about the size of a cigar box, easily stored under the seat, where the temperature will be slightly cooler than the rest of the cabin. Many models also feature a cable lock that can anchor it to the seat bracket or other part of the car.


Furthermore, any ammunition that’s repeatedly exposed to high heat and humidity should be cycled out of use in a carry gun. If one goes to the gun range every so often – say every few weeks – then one has a method for disposal. It’s better to have ammunition that can implicitly be trusted, rather than trust that nothing has gone wrong.



About The Author

Born in southeastern Washington State, Sam Hoober graduated in 2011 from Eastern Washington University. He resides in the great Inland Northwest, with his wife and child. His varied interests and hobbies include camping, fishing, hunting, and spending time at the gun range as often as possible.