Ammo Cooking off in a House Fire

[buck00]

I was recently at a buddy's house. He has a gun safe stuffed with 40 firearms. Next to the safe he has a mountain of various ammunition- well over 10,000 rounds.

I asked what would happen to all the ammo if the house burned down? Would the ammo "cook off"? Would responding fire fighters be in danger of being hit by rounds popping off?

Does anyone here have a story about a house burning down and ammunition cooking off?

 

[One of Many]

Ammo will cook off given enough heat for a long enough time; that is why when a round fails to discharge in a firearm, you wait a minute before extracting it from the firearm.

Ammo tossed into a fire or trash burning barrel will discharge, but with little force; since the cartridge is not contained in a chamber, the brass will expand or rupture, releasing pressure before any significant motion occurs. What little motion does occur will be the cartridge case, since it is lighter than the bullet; the bullet will stay put and the cartridge case will move slightly. The noise will be a popping sound, similar to a cork being released from a bottle.

There is little danger of injury to anyone near this when it happens; it may frighten people when they realize what is happening, and their fright may cause them to do something that results in injury.

 

[Outlaws]

One of Many,

That sounds completely logical, however is there any legitimate source of firearms online that would confirm that?

There is always that little voice in the back of my head saying, "you really wanna find out the hard way?"

I would assume then that setting primer off with something would cause the same non-projectile effect?

 

[Hemicuda]

My father, an AVID collector had a housefire in 1981, where 90% of his guns were lost (both of the 2 I owned then survived... I was 10)

all the ammo did (literally thousands of rounds) was to cook off as "One of Many" said...

I was a little kid, but I remember the popping... and the firemen weren't worried in the least...

 

[Jim K]

Near here a while back there was a sporting goods store burned down. There was a lot of ammo "popping" but that was all.

A loaded gun is a different story; whether the round is fired normally or cooks off in a fire, the bullet does the same thing. Also, large quantities of powder (yes, even smokeless) can be explosive. There was no problem in that store because the powder was in the original packages, but at one time powder could be bought in 150 pound barrels and those could be very dangerous if ignited.

Jim

 

[M2 Carbine]

In 1995 my gun shop burned to the ground.
In it I had 30+ thousand rounds of loaded ammo, thousands of primers, about a dozen cans of gun powder, seven guns, 4 reloading presses and a LOT of other firearms and ammo loading junk.
It was a very exciting morning, and quite an education.

First, off don't believe that all the ammo will just pop and maybe split the case but is no danger. Most unconfined ammo will do this but there always can be the exceptions to the rule. Some ammo may explode with enough force to make the bullet or case deadly.

Second, powder, in the original cans is very safe. It does not explode. The can top or bottom just poops out and the powder burns.
The exception is Black Powder. It explodes.
Cans, like WD40 do explode. They are much more dangerous than gun powder.

After the fire my Wife and I spent two days sorting out what we could to show the insurance adjuster.

These are some of the gun powder cans. The exploded ones are Black Powder or stuff like WD40.
Note the bullet holes in the center cans.
All the loaded ammo was stored in steel GI ammo cans. That means that that those bullets went through, at least, a steel can before going through the powder cans.



This full can of FMJ 9mm reloads was about 15 feet from the fire. The heat caused about 40 rounds to explode.
Two things, the rounds appeared to explode with some force but this did not cause any other rounds in the can to explode.
I eventually shot all the surviving ammo.



The ammo did strange things in the steel cans.
A half can of AK ammo burst, with some force, but not a case or bullet broke through the can. This is it after I opened the lid.
Note the bullet and blast holes in the other cans.



While other cans had multiple holes in the very beat up cans.
It must have been very exciting in this 50 cal GI can for a while.
There were a number of bullet holes in the stuff that couldn't completely burn.




IMO the only way to store ammo is in GI steel cans. Some of the ammo did eventually blow through the cans but not before anyone that is able would have escaped the fire.

As far as fireman getting close to a fire that contains a lot of ammo?
I wouldn't let the fireman near my shop until it was burned out, and that was before I saw the bullet holes.

 

[Crawlin]

Ok then, this raises another question for me. If a gun with a round loaded in the chamber cooked off, would it not be just like it fireing. And if so, "could" work the action enough to chamber another round? I know that there is nothing to hold the gun in order to properly work the action but it is a possibility right?

 

[M2 Carbine]

My guess would be that the rounds in the magazine would cook off before the one on the chamber.

If not, I would suspect another round could be chambered and cook off.

 

[PvtPyle]

I guess this is related. We hit a compound in Afghanistan that had munitions burried down as far as 40 feet (near as we can figure based on the size of the hole). They determined that the tower was too unsafe to clear, so the SEALs rigged it with demo. After the initial explosion it continued to cook off and fire rockets out of the hole for seven days. I have a video of the initial blast, it turned the morning sky black.

Some people say the same thing will happen at my house . I think I just need to stock up on high order munitions so it all goes at once.

 

[kungfuhippie]

storing the ammo in steel cans is like making a bomb. as the powder burns off in the can the pressure will build and potentally explode sending its contents flying as schrapnel. Mil-surplus ammo cans were made as an efective means of rugged storage and transportation of large quantities of ammo. Not really as protection. See how that 9mm can ruptured, it had a blast area where the can failed and pressure was relieved.

When I was in Ecuador I lived about a mile from a naval base and their armory went up in flames on night. Impressive sight, too bad people lost their homes and some lost their lives. Bullets and mortar shells (or what ever they put in their ships) shot off and many penetrated steel roofs. In all the comotion people ran out into the streets and down to the base to try and help, leaving their doors open. Many a BG walked right into homes and stole all they could. A very sad occurance.

Setting off a firework in your open hand will give you a nasty burn.
Setting off a firework in a closed hand will give you a nice stump.

Store the ammo in something that's not air tight and you'll be safe.

 

[silhanek]

My guess would be a round cooking off in a chamber would fire, but the gun would malfunction/misfeed before loading the next round to fire. Most handguns rely on resistance by the shooter and won't quite cycle right without that. Ex. limpwristing.

 

[gezzer]

Check with the NFPA, I am a retired FF/investigator, All the training in my Dept. State and Federal academys is ammo is not hazardous to FireFighters.

Also the NRA has stated this , Do some reasearch.

 

[swingcatt]

Having running my stint in fire/rescue in VA about 10 years ago, I have three stories concerning this:

1. 10-70 dwelling fire on Dec 23, 1996, remember it well, because I was the first one on the scene. Boxes of ammo stored in a back bedroom cooked off on the other side of a wall. I could hear them popping in the other room, but didn't thing twice about it until we went back through the house looking for hotspots and found the cases under a bed. I remember it sounding a lot like loud popcorn. The ammo consisted of about 6 or 7 boxes of pistol ammo and a couple of cases of bulk .22 lr.

2. Went to an explosive HAZMAT class sponsored by Hercules Powder. It was put on at the local National Guard Training Complex. They took various boxes of ammo put them in their cardboard shipping boxes and put them on a special grilling apparatus. I remember only the .30-06 breaking the cardboard boxes. They also showed film of various rifle rounds being held horizontally and put over an open flame. A piece of construction paper was put 12" in front of it. None of the bullets had enough energy to even break the heavy paper.

The moral of those stories are if the cartridge isn't contained by a chamber or barrel, the gases from the burning powder are quickly dissipated on all sides of the bullet at once when it leaves the case. Since it can't build up pressure, it can't have any velocity.

Now, #3 is a bit more intersting, and wouldn't you know it's the only one that was NOT witnessed by me, (but I did see the pictures of the hole in the ambulance). Seems one of the neighboring units rolled up to standby on a 10-70 flue fire that was going badly. The old rock mantle had cracked and the fire had seeped into the walls and was quickly engulfing the living room. No one thought to remove the old muzzleloader from above the mantle, I mean, who would put a loaded muzzleloader above thier fireplace, right? Ba-whoom! Shoots thru the wall and lodged in one of the interior cabinets of the rescue unit.

So yes, one cooking off inside a firearm would be the same as discharging it. Rule #3 of gun safety "always keep your firearm unloaded until ready to use it". SC

 

[CB900F]

Outlaws;

The NRA published an article on just this subject in American Rifleman. AFAK it's not online, you'll just have to (gasp!) access it the old-fashioned way.

900F

 

[buck00]

The moral of those stories are if the cartridge isn't contained by a chamber or barrel, the gases from the burning powder are quickly dissipated on all sides of the bullet at once when it leaves the case. Since it can't build up pressure, it can't have any velocity.

That is the technical explanation I sought. I wasn't sure if the rounds would shoot off during a big fire.

M2 thanks for the pics of your store. I hope you had good insurance!

 

[M2 Carbine]

Yeah, everything was covered at full replacement cost but like in any loss like that, there were many things that no amount of money can replace.

 

[rudolf]

Stacking ammo into a metal enclosure actually creates a chamber, as the mass of the ammo surrounding a single round combined with the metal enclosure create enough of a chamber to let it go bang.
If you have a look at how your ammo is normally packed you will see that there is enough air (or plastic) around each cartridge to let it burn safely.

 

[RyanM]

Don't know if it's true, probably not given what everyone else has said, but I think I read somewheres that the primers can pop out of cartridges at very high velocity, if they cook off.

 

[TheHardcase]

It's been one of my many concerns

We have a shed next to the house that holds the bulk of our ammo inventory. We've got about 2500 rounds in the house, the rest insulated and sealed in the shed. If that shed went up, I have no idea what kind of damage would be caused by all that ammo cooking off.

 

[Zach S]

Not long after the last time I saw this come up, I asked a fireman about it. He said that aerosols worried him more than ammo, even after I mentioned that I normally have ammo stored in in piles of around 1000.

 

[Lupinus]

it can and will happen

But as has been said it will likely be without much force.

It can happen, but it is more likely not to.

 

[Old NFO]

+1 on Swingcat's entry. I spent 10 years doing Volunteer Fire/Rescue in Orange Park, FL. I saw a "number" of house fires with ammo therein. Most just cooked off, what really scared me was the one time I was putting out a bathroom and the corner of the bathroom disappeared as the 00 buck that had cooked off in the chamber of the 12 ga. exited the house. Another firefighter with our department did have a 5.56 round get lodged in his boot; it also appeared to be a cook off inside an M16 that was stored in an adjacent room (we did find a case in the breech minus the bullet but with no strike mark on the primer). We all heard a "loud" crack about the time he got hit in the foot (and knocked down).

Slight aside... Also had a guy tells us as we rolled in one night, "Oh yeah, there is a case of dynamite in the back corner of the garage, y'all might wanta be careful of that..." Believe me that is FASTEST we ever put out a garage fire and from 50 yards away with the turret mount...

 

[Ben Shepherd]

Bulk primers stored in bulk in tighly closed containers are bad, very bad. I.e. 5,000 or so in a steel GI can.

Ammo isn't really a risk due to all the gear firefighters wear.

 

[stevelyn]

Basically all you'll get with ammo in the open is a POP......Pffffft!
Ammo stored in ammo cans may burst at the weakest point, but as the pressure bleeds off nothing further will occur.

Primers in bulk could be a problem. Smokelesss powder as long as it isn't contained in a pressure vessel will just burn.

 

[mp510]

When Hoffman's (big gun shop in Newington CT) burned down a bunch of years ago, the Fire Department closed down the Berlin TPKE about 1 mile in each direction. A lot of ammo did "cook off", but IIRC, the projectiles did not have anywhere near the velocity that they would have had if they were fired in a weapon.