Ammo Cook-Off (Specifically, what temperature?)

[JohnHL]

No, I'm not talking about the Olin-Winchester Corp. Annual Company BBQ.

At what temperature (like in a fire) will a loaded round "go off"?

And what ignites first from the heat, the primer or the powder?

John?

 

[Nevada Ed]

It ain't going to happen.

Todays pistols need 1,000's of rounds through them to get a barrel hot enough;

and I doubt that any one with bare hands could hold on the the grips
before it even got close !!

Pipe dream.

 

[ralph7]

It ain't going to happen.

Todays pistols need 1,000's of rounds through them to get a barrel hot enough;

and I doubt that any one with bare hands could hold on the the grips
before it even got close !!

Pipe dream.

He's talking about a fire, Ed!

 

[s&wchad]

I don't know the ignition temp, but ammo that goes off in a fire is spectacular but relatively harmless. The bullet/shot travels about as far as the casing/hull, unless it's contained in a chamber.

 

[JohnHL]

Yes, I understand about unchambered rounds driving the case farther than the projectile because of the difference in mass.

I am just curious about the external temperature at which the combustibles in a loaded round ignite, and which has the lower ignition temperature, primer or powder.

Perhaps some of our Firefighter (or insurance) members may have studied this.

John

 

[CH4]

Actually, pretty benign. About the same as a firecracker.


[ame]https://m.youtube.com/watch?v=TDYMcrb54t4[/ame]

 

[Alk8944]

Strictly "cook-off" refers specifically to guns getting hot enough to cause a chambered round to fire from the heat. This only happens with machine guns. Wrong term!

Specifically I doubt anyone knows, or cares, except Underwriters Laboratories, they test for such things. You might look them up and give them a call.

The threshold temperature is probably around 400 degrees F. but definitely below 650 degrees, since a primer will be set off if accidentally dropped in molten lead, and lead alloys melt at approximately this temperature and can exceed 800 degrees. Whether the propellant or primer will go off is a moot point, because any form of fire greatly exceeds 650 degrees! The only time there would be a real problem if if a loaded firearm is involved in a house fire and gets hot enough to cause the chambered ammunition to fire. This does happen.

Someone awhile ago posted that his gun, stored in an oven had the ammunition in it fire when the oven was turned on to heat up! No idea how hot the oven got, but it was enough. And some ask "How stupid can people be?"

 

[robertrwalsh]

For some reason or other I recall that the cook-off temp for modern primers is about 375 degrees. Way back in the ancient days the NYPD used to "suggest" to cops that if they wanted to effectively hide their unattended weapon in their home they should put it in the stove as no burglar EVER looked in a stove. After a few dead stoves due to the wife-GF not checking the stove before lighting it off this suggestion was withdrawn.

 

[peterGun]

Actually, pretty benign. About the same as a firecracker.


Box of Bullets in a Campfire - What Happens? - YouTube

Neighbor’s pole barn caught fire and it was his ammo cooking off that woke me, once I opened the window I could tell it wasn’t fireworks.

Dude must of had quite a stash because it went on for about 15 minutes, when I walked down to the road for a better look I realized the fire truck was parked quite away from fire


Sent from my iPhone using Tapatalk Pro

 

[Rob613]

https://youtu.be/8ad9e0mO8Q4

 

[ISCS Yoda]

I don't know the ignition temp, but ammo that goes off in a fire is spectacular but relatively harmless. The bullet/shot travels about as far as the casing/hull, unless it's contained in a chamber.

So, Chad is correct. In 2018, as I have oft noted, I had a house fire. On a chair in my dining area I had 1000 rounds of 9mm NATO ammunition. I think it was two boxes of 500 each but it might have been one large box of 1000; I can't recall presently. The entire thing cooked off. It sounded like the 4th of July. The firefighters did not enter until the fireworks ended.

Naturally, you could get an eye injury from flying brass or bullets but, otherwise, when ammunition cooks off like that it is relatively harmless, as noted by Chad.

BUT!!!!

Unexplainably, my neighbor across the street found a spent case in his backyard. That means it flew out a window, went up high enough to cross the street and go over his roof, and land in his backyard. I expect that that brass case could have caused a nasty injury had it hit anyone at the beginning of its launching.

I found some spent brass in the street myself but that was only halfway to my neighbor's house.

On the other hand, the gun in this picture was in a cabinet right by the wall where the hottest part of the fire was and it got torched and scorched:

But the ammunition was intact!!!!

 

[Doug M.]

My dad served in WW II as a tech nerd. Sometimes in their spare time, as young men of military age are likely to do, energy and curiosity overran their better sense and they put artillery shells in a fire. Case moved, projectile not much.

 

[Model19man]

When I was a kid maybe 55 years ago we put a box of 22 rimfire ammo in a campfire to see what it would do. It was generally unsatisfying. The rounds sort of sizzled as they opened and burned. The fire got real bright every time it happened. It wasn't like firecrackers as we thought it would be. Maybe center fire ammo would be different.

 

[Nevada Ed]

Oh a fire.

In that case if you try it;

Here's your sign........................

 

[.38SuperMan]

Contact the manufacture of each component you’re interested in. The will have the data on flash point of each powder the make. Primer manufacturers will have the same. That’s days that probably required to get the ORM-D Hasmat label. I have a degree in chemistry and know that data for flash point, melting point and a ton of other data exists for pretty much every known compound on earth. Call the manufacturer, they’ll have the analytical data on their products.

Always best to go to the source of the most accurate data available, the folks that make the product.

 

[SnidelyWhiplash]

When I was a kid maybe 55 years ago we put a box of 22 rimfire ammo in a campfire to see what it would do. It was generally unsatisfying. The rounds sort of sizzled as they opened and burned. The fire got real bright every time it happened. It wasn't like firecrackers as we thought it would be. Maybe center fire ammo would be different.

Take a .22 and lay it across the terminals of a 9v battery. Eventually it will heat up enough to split the case.

Safety advice…please don’t actually do it…while chances of injury are small there’s no way to predict how it ultimately will rupture.

 

[ArchAngelCD]

There is one good way to fine out. Throw some ammo in a fire and when it goes off use one of those infrared thermometers to check the temp of the fire where the rounds went off. No guessing there, just a fact.

 

[JohnHL]

I don't know whether it is a disappointing indictment of reading comprehension skills, or the adolescent attraction of pyrotechnics, but nearly all responders fixated on throwing ammunition into a fire which was NOT the question.

I didn't know the answer to my question when I asked it (I do now) but I thought more folks here on the Forum would.

In all fairness, only two came close.

John

 

[JohnHL]

Strictly "cook-off" refers specifically to guns getting hot enough to cause a chambered round to fire from the heat. This only happens with machine guns. Wrong term!

While the term, "cook-off" is commonly used among firearm enthusiasts as the "auto-ignition" of loaded cartridges in the overheated chamber of a machine gun, according to standards and definitions used in an analysis prepared for the U.S. Department of Energy by the Sandia Laboratories on the specific subject of the "auto-ignition" of firearms propellants by the application of heat alone, "cook-off" refers to the "auto-ignition" of any combustible (by heat) while in containment either open or closed.

Specifically I doubt anyone knows, or cares, except Underwriters Laboratories, they test for such things. You might look them up and give them a call.

Wrong again...

My research has uncovered that quite a few people care (myself included) and a whole lot of people know, and they are mostly (but not limited to) the companies that produce powder and primers.

That you don't know certainly doesn't mean that there isn't "anyone" who knows or cares, unless of course you are like when I was a teenager and my Father used to tell me, "The sun doesn't exclusively rise and set on your rear end, John". (I cleaned that quote up a little.)

The threshold temperature is probably around 400 degrees F. but definitely below 650 degrees, since a primer will be set off if accidentally dropped in molten lead, and lead alloys melt at approximately this temperature and can exceed 800 degrees.

Congratulations.

Through a form of circuitous logic and frightening observations, you have accidentally come somewhat close to answering half of my question.

Now that I have responded to what seemed to be a superior yet dismissive answer on your part, please understand that I have read a good many of your answers to other's questions, and you typically appear to me to be knowledgeable (albeit irascible) on most gun related subjects.

John

 

[JohnHL]

For some reason or other I recall that the cook-off temp for modern primers is about 375 degrees. Way back in the ancient days the NYPD used to "suggest" to cops that if they wanted to effectively hide their unattended weapon in their home they should put it in the stove as no burglar EVER looked in a stove. After a few dead stoves due to the wife-GF not checking the stove before lighting it off this suggestion was withdrawn.

Robert, yours was the most knowledgeable answer on the subject.

While the Forum was not my friend today, Google was.

I discovered the answer is somewhat dependent on pressure, but the best answer is that both primers and smokeless propellants "auto-ignite" at around 375 degrees Fahrenheit.

Black powder "auto-ignites" at around 840 degrees Fahrenheit.

John