Hollywood would have you believe that fire “sets-off” ammunition—to the point where good guys and bad guys alike run for cover. The media buys into this myth as well. To wit: “The residence, owned and occupied by Butch Jones, was engulfed in flames when firefighters arrived,” news-journal.com reports. “Jones was trapped inside.” What’s worse, Jones had a shotgun, a rifle and several handguns in the home, along with approximately 8,000 rounds of ammunition, which were ignited by the blaze. Ammunition began exploding from the heat of the fire.” Exploding? Time to reach for my coffee cup . . .

There will not be bullets zipping around your home [in a fire], nor should there be an explosion. Since most bullets weigh more than the case—the bullet will remain in place and the case will only move a few inches. Also, since the ammo is not confined, it will not discharge like it will in a firearm chamber. It will only “pop” a little.

That would be commentator coffeecup back in the day over at defensivecarry.com. The information doesn’t get out much. Back to the conflagration in Cass County Texas:

Jones’ grandson Dustin Jones was attempting to move a boat and trailer away from the fire when he was suddenly hit in the upper left leg by exploding ammunition coming from inside the house fire. A possible stray shell casing may have been the culprit. An ambulance was requested.

Yes, well, here’s the real problem: firefighters. Despite the physics of the situation, if firefighters hear that you’ve stashed 8k rounds of ammo inside your domicile they will most likely “err on the side of caution.” In other words, they’ll listen to the pops from a distance and let your house burn to the ground.

You might say STFU during the fire fighting phase of an emergency response but that would be wrong. The firefighters need to know what they’re dealing with and where. Their lives are more important than your house.

A fire resistant ammo safe is a better idea. I know: you don’t really need one. But it could save your house from immolation and you do you need a bigger gun safe. (Who doesn’t?) Go on, admit it: the idea of a entire safe full of ammo thrills you to the core. Win win?

130 COMMENTS

  1. My garage is not attached to my house. Most of my ammo and all of my cleaning supplies is stored there. We have mild weather in the bay area and I don’t worry about the fairly mild temperature and humidity swings bothering my ammo.

    • Where you living there during the Oakland East Bay fire in the ’90s? There was so much smoke that by 3PM in San Francisco you could barely see the sun in the sky. Those dried eucalyptus trees burn fast.

      • Yes, my sons and I watched a convoy of fire trucks from the central valley area heading up the freeway and into the zone. Help was coming from all over.
        Nothing but respect for firemen.

        • I really wanted to be a firefighter, but I love guns too much. The CA wildfires get pretty bad, and those guys work hard. I’ve seen them save homes that I thought were toast. They’ve got my respect.

        • It’s been a few years but if I remember correctly the convoy I saw was fire trucks from Livermore, Tracy, Stockton and Modesto. They were in the middle lane of the freeway with all lights going.

          My sons were young then and they were suitably impressed. Hell, so was I.

  2. There was a mythbusters episode about this. They threw a bunch of ammo of varying calibers into a campfire, and placed sheets of dense foam around it to see what came out. As RF writes, mostly it was casings exploding, though I seem to recall that in some cases the casing and the bullet separated. The casing fragments were moving at sufficient velocity to draw real blood or even take out an eye if one were unlucky, though a fireman in full bunker gear with a facemask and helmet would be fine.

  3. I am guessing the exception to this rule would be shotgun shells? I cannot find the story as this did not make the national news but I seem to remember reading a story of a boy who was killed 10-15 years ago when his father threw a box of 12 gauge shotgun shells in a bon fire on the 4th of July; this happened in southern Wisconsin. Anyone from the area remember this story? I was maybe 10 or 12 when it happened so all of the details are a touch fuzzy. Again; we are talking about somewhere between 1996 and 2000; most papers in the area did not have websites so this might be a little tough to hunt down.

    • Unless they were something extremely unique, like full brass shells or something incendiary, the shot load weighs many times more than the shell, and the effect will be the same as brass cased pistol/rifle ammo.

      • To my mind the plastic shell would seriously soften or melt before the powder cooked off. The gooey plastic would be an easy escape route for the powder gasses.

        • By “full brass” I mean old blackpowder-style shells that are completely made of brass. Any modern shell, paper or plastic, would indeed deform before it went off.

    • It seems that the casing would burn or melt on a shotgun shell quicker than the powder would explode but then again I am not one to tempt fate and try to prove that theory.

  4. It’s worth pointing out that very few safes are fire “proof”, unless they are extremely large and extremely expensive. Most “fire proof” safes are designed to withstand a certain temperature for a certain period of time. Exceed either of them, and whatever is inside is going to get cooked anyway.

    A much more cost effective (and fire “proof”) method is to store your ammo in ammo cans somewhere in the basement of your home, and surround that area with ceramic bricks. They will reflect much more heat for much, much longer, and such a setup is considerably cheaper than a fire safe with a several hour rating.

    • I worry about the gas buildup in a safe. I have two. One is a Stackon, the other a local outfit (Hall’s) who claim their safes keep the contents cooler (140F vs 350F) than most commercial safes because they have no holes for electrical cords. I have no real proof of this comparison, but they do have two safes they bought back (replaced) after houses burned down on top of them, and they look remarkably fine inside.

      If this is the case, a commercial safe, including presumably Stackon, should be able to vent some gases at a reasonable enough rate to keep the safe from bursting its seams or turning into shrapnel. The Hall’s safe, not having any venting, presumably wouldn’t, but it would take more fire to burn the ammo inside.

      Any thoughts? I have always wondered about this, and maybe someone here knows more about that.

  5. Another good idea I forgot to mention is to place a fairly large automatic-release fire extinguisher near your ammo stash. There are many of them on the market, primarily used for trailer protection and auto racing. While it won’t prevent a home fire, it will buy quite a bit of time for the area in question in the event of a fire.

  6. I fought a fire last year where the house exploded. Guy had a ton of ammo in the basement. It cooked off while we were fighting the fire and posed no danger to us. Just sounded like little firecrackers going off at random times. Interestingly enough, the ammo was stored in a safe, but he had either left the door open or the force of the explosion had blown it open.

  7. There is a danger if any ammo is chambered in a firearm in a fire. Those rounds will act just as if someone had pulled the trigger on them. That would include ALL the rounds in a revolver, making it a pretty effective bomb.

  8. UM, sorry I’m conflicted. If I show up to your house and you don’t tell me you have ammo in there and I find out about it, you and I are gonna have words before I introduce you to the nearest deputy and or constable (This is speaking as Asst Chief of the VFD). When I am on scene commander, I have to know anything and everything about what my folks are fighting. Is that going to keep me from committing firefighters to the attack? No, I know they’re well protested in their bunker gear. It may change where I put emphasis on getting water. Kinda like trying to keep the propane tank cool and focusing water on it when the house is burning.

    • You’re gonna introduce the owner to the police? Uh huh. And you’ll please cite the state or local law requiring homeowners to notify the firefighters about ammo in the home. I’m aware of no such regulation in our state, at any rate.

      • I don’t know of any law myself that requires the disclosure of ammo in your home to firefighters. However, withholding information from Emergency Responders that they deem important to safely do their job efforts can be seen as an act of negligence or intentional endangerment. I’m not saying I agree with that, only that many a DA would be happy to pursue charges no matter how absurd if the “offense” is believed to have endangered the Emergency Responders. I remember reading a story in the newspaper many years ago about a man whose house caught on fire. When the fire department showed up, he did not tell them that there was a drum of oil or fuel in the garage. The drum ended up exploding and injuring several firefighters (though nothing life threatening). The man was charged with and convicted of reckless endangerment for not informing the fire department about the fuel drum. With society’s misconception of guns and ammo and how they might behave in a fire, I would imagine that you could expect a similar response if it was discovered after the fact that you failed to disclose the presence of ammunition in the building.

    • Why would you involve a LEO? I understand the need for IC and the safety officer to keep crews safe, but typically when someone’s house is burning down they have other stuff on their mind than, oh yea I have some ammo in a closet on the charlie delta corner, I should tell the FD. We weren’t told about the ammo in the house that exploded, because when the owner’swife showed up she was a little more preoccupied by the fact that her house was destroyed and her husband was missing.

  9. RF your quote from CoffeeCup is just plain wrong. It’s not hyperbolic, it accurately describes the reaction as a violent expansion of energy with the potential for destructive force. Perhaps Coffeecup needs to re-visit some basic science classes. Every time the firing pin strikes the primer on live ammo there should be an explosion. The primer ignites the powder, the powder expands violently (ie explodes) propelling the round from case. In a case of auto-detonation the gunpowder ignites when it is heated to around 500 degrees Celsius. Science it’s good for you.

      • http://www.youtube.com/watch?v=m64ClfsXe_4

        At 2:07 the presenter explains what happens when a firing pin strikes a primer. There are two explosions, the first is created by the action of the firing pin striking the primer. This causes the primer to explode, that explosion ignites the creating a larger explosion which propels the projectile out of the barrel. In the case of the burning house an explosion is created when the case is heated to the ignition point of either the primer or the propellant.

        • Gee what the hell am I bothering with all these expensive guns for then? To send rounds downrange, I just need something to hold the round steady and then ignite the primer!

      • In Vietnam, when we abandoned a position, we threw the belts of ammo that had been exposed to the weather into fires or buried it. The ammo in the fires just made popping sounds when the brass casings split. There were definitely no bullets whizzing around. I don’t know if the primers went hot or the powder in the rounds.

    • Since the edit is not working…..

      The reporter accurately used the word “exploding” to describe what the ammunition was doing. As the ammunition was exposed to heat the temperature of the shell case reached the ignition point of the gunpowder. When the gunpowder ignited it created several small explosions, i.e. the ammunition began exploding.

      • If engulfed in fire, the case is expelled from the bullet unless the round is in a firearm. Without a barrel to direct the gasses and accelerate the bullet velocities are very low.

        Science IS good for you.

        • Yes, and what action expels the case from the bullet? Oh right, an explosion. Yes when ammunition is engulfed in fire an explosion expels the shell case from the bullet unless the round is chambered in a firearm, in which case the casing is held in place by the firearm and the round is propelled out of the barrel.

        • Firecrackers explode because the gases are contained in a tight package until the pressure exceeds the strength of the case.
          Gas buildup = Explosion

          cartridges are not tightly contained, by design they are required to open up. The bullet is moved from the case with minimal pressure and the rest of the gunpowder simply burns.

          Call it an explosion if you must but it’s not as dramatic as you claim. It’s more like a fart.

        • GS65OG I never claimed the explosion was dramatic, I merely refuted CoffeeCup and RF in the fact that the journalist was correct in saying that the ammunition exploded during the fire.

          The journalist wrote,”Jones had a shotgun, a rifle and several handguns in the home, along with approximately 8,000 rounds of ammunition, which were ignited by the blaze. Ammunition began exploding from the heat of the fire.”
          RF called into question the voracity of the Journalist s statement by questioning whether or not ammunition explodes when introduced to heat. RF then quotes some random internet poster , coffeecup, who states that, “There will not be bullets zipping around your home [in a fire], nor should there be an explosion. ” My point was that coffeecup is incorrect and by extension so is RF in questioning the supposed use of hyperbole by the journalist. Ammunition does in fact explode, whether it be from the firing pin striking the primer, or the autoignition of the powder during a fire. I never speculated or commented on the extent of the explosion other than to acknowledge it’s existence.

          RF made a couple of erroneous claims in this posts prior to the multiple edits. The first was that the ammunition didn’t explode and the second being that you should STFU to the firemen about the amount of ammo you have when your house is on fire.

          My comments were specifically addressing RF’s insistence that the rounds weren’t exploding. However, exploding is what ammunition does best. It is designed to be a controlled explosion, a small brass and lead shape charge if you will. Without the two small explosions that happen inside of the shell casing the round would never leave the gun.

  10. I’m not sure about the idea of putting all your ammo in a safe. Aren’t you turning a bunch of small firecrackers into a really big bomb? By placing them into the safe you are essentially creating a really large pressure vessel. I’m sure it would take a while to get up to a temperature that would cause things to cook off, but once it started, wouldn’t it be more of chain reaction if everything was confined in a safe?

  11. Several years ago, we had a neighbor across the street commit suicide by attempting to suffocate himself with the car running in the garage. The police are not entirely sure what happened, but it looks like he tried flooring the car in neutral to speed up the buildup of exhaust. Somehow the car got put into drive, and slammed against the back wall of the garage, but the accelerator was stuck or something. The tires (front wheel drive) spun out and started smoking and caught on fire really fast. We were eating dinner when we heard the car crash into the back of the garage. We immediately rushed outside and in a matter of seconds the whole garage was engulfed in smoke and flames. My Dad tried running into the garage but the heat and smoke was too much for him to even get in. 2 or 3 minutes later, we heard a dozen or so loud popping noises coming from the car. I found out later from one of the responding police officers (an old high school buddy) that a revolver (I want to say he said it was a .357 or .38 Special) was in the glove compartment and all the ammunition cooked off. However, none of the fragments from the casings or the bullets were able to exit the glove compartment including those in the cylinder. Apparently there were also a couple of speed strips in there as well. Needless to say, the neighbor did not survive.

    • Well, ammo that is encased in a firearm is a completely different story. Loose ammo that overheats pops and the case moves away from the bullet as the bullet is heavier and the brass can expand. When the case is enclosed in a cylinder of a revo, that round is going to expel the bullet since the case is contained in the cylinder and the expanding gasses have to go somewhere.

  12. I’m a firefighter/paramedic in a rural area. Everyone has guns. As noted elsewhere, I don’t worry very much about ammo in a fire (and I’ve encountered it a few times). It makes a pop, and that is about it. Properly stored smokeless gunpowder sounds like a mortar though (I suppose as the container disintegrates) , but the reaction stops/slows dramatically when it is no longer under pressure.

    I worry more about propane tanks, gas tanks and so forth.

  13. 20 years of firefighting in the metro Atlanta area. Ammo never a problem, pressurized containers stored in the structure, a problem. Meth lab in the structure a problem and usually the cause of the explosion leading to a fire. I know of one incident where a firefighter performing defensive operations (outside of the structure) was injured due to a round in the chamber cooking off. He suffered a gun shot wound in his chest but did not penetrate his chest wall.

  14. A good deal of this debate is being driven by some common misconceptions of what gunpowder actually “does”.

    Gunpowder is the lowest of ‘low explosives’. Take any gunpowder from FFFg to 777, lay down a rail and ignite it. It will burn at differing rates, but technically speaking it deflagrates (burns). It drives that bullet down the barrel the same way it makes that firecracker go ‘pop’ – it burns and the gas expands in a confined space until something moves out of the way to allow the gas to expand.

    Even our current nitrocellulose (single base) smokeless powder just burns. It does so quickly to the human eye, but when compared to what a high explosive does, it is the tortoise compared to the hare. The only way you get that satisfying “boom” is to confine that reaction to a container of some sort.

    I could write a two-pager on this but to simplicate and add lightness:

    RDX (C4)/HDX/JDX/HNIW/ONC/Whatever detonates
    Gunpowder deflagrates

    Deflagration (burning) just does not produce the velocity required to make those rounds in your campfire do anything more than go ‘pop’.

  15. I wonder if an insurance carrier could use your ammo as reason for refusing reimbursement, or at least full reimbursement.

    For example:

    You’re house catches fire and the fire department responds quickly. You tell them that you’ve hot 8K rounds of ammo in your bedroom closet uncontained. They decide not to respond due to the danger of the ammo and your house burns to the ground.

    Could an insurance company deny payment because your actions prevented the fire department from putting out the fire?

    Just a thought.

  16. As 16V above notes, there is a significant difference between deflagration (which is what happens when an ammunition cartridge is fired) and detonation (when a chemical mixture or compound explodes). Wiki has a good synopsis;

    http://en.wikipedia.org/wiki/Deflagration_to_detonation_transition

    Also, it was mentioned above the ammunition primers “explode”. Well…not really. Primers ignite. Much like a match head when struck. When the primer cup is struck by the firing pin, some of the primer material (typically a mixture that includes lead styphnate and ground glass or silica) is crushed between the now indented cup and the anvil. Friction from the crushing causes the priming mixture to ignite. Once ignited, the flame front propagates across the mixture and because the flame is confined within the primer pocket, some of that flame and burning material is directed through the flash hole thereby igniting the powder.

    As an aside, a fairly good and very dramatic example of deflagration transitioning into detonation, is the PEPCON explosion in Henderson, Nevada on May 4, 1988.

    • ‘Xactly. Which is why one can take a bunch of match heads and make a big firecracker – or one could put them in a pile and they’d just burn.

  17. I’m not a Physics professor, but I can tell you from personal experience that if a garage full of ammo burns there are explosions. My in-laws live in Colorado Springs and if you do a little research you’ll find a story in the local newspaper from a few months ago about a house fire with a garage containing several thousand rounds of various calibers of ammo. The in-laws live about three houses away and, after they were let back into the neighborhood, they found brass scattered around their backyard. Granted this brass probably didn’t have a lot of energy left, because they found no dents or holes in anything, but it did travel. The house next door did have holes in the vinyl siding. I took several walks past this house and I kick myself now, because I didn’t take any pictures.

    • Keith, If you pile ammo in a fire it will go off, no doubt about it. Would you want to be roasting marshmallows over a pile of 7.62×39? Nope.

      Even very high power (.50 BMG) rifle rounds can’t move that brass more than a few feet on its own power. However, what will send brass flying 20 feet is a 3 inch attack hose at 300+ PSI set to stream. Even an inch-anna-half reel hose will clean your garage in a hurry. As to the holes in the neighbor’s siding, any hot embers will burn clean through vinyl, especially the lighter grades. If one has vinyl and your neighbor has a fire, you can pretty much count on replacing it.

      Not calling you a liar by any stretch. Just offering that the aftermath which you witnessed is perfectly explicable without stuff going ‘ka-blam’ as in the cartoons.

  18. I use a 2 drawer, locked, legal size fireproof file cabinet that I keep in my garage. I’ve had it for years – used it in my business when I had to protect client’s magnetic media. Holds a lot of ammo. They are expensive new but can be found on the cheap used, and they don’t go bad. Mine weighs a ton, well not really but about 300 pounds. It was designed for magnetic media so it is a better fireproofing alternative than most gun safes because of the higher ratings.

    J.

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