Fire in my shop caused by old powder.

[Mills]

My father in law gave us a whole bunch of ammo when he stopped hunting and shooting. We probably need to get rid of the stuff as it has been in our garage forever. Lots of steel shot and 1 oz+ magnum 28 gauge loads. Stuff you would not want to shoot in any gun, let alone a vintage double

[Elk Hunter]

Personally I wouldn't be too concerned about old ammunition as the amount of powder in them is very small. But if you're concerned about it by all means get rid of what you have. The problem comes from having bulk powder decompose and the resultant heat buildup causes it to ignite spontaneously. In my particular case there was several pounds of WW-2 rifle powder in two plastic jugs that I knew was going bad and I didn't pour it in a bucket of water as I intended. I had planned on putting it on the lawn as fertilizer and just didn't get to it soon enough.

[John Powers]

Something I would also like to mention is notifying the local fire department and letting them know you have large quantities of powder. I have well over 100 lbs of smokeless and 25 lbs of black powder and if my shop area catches fire, I certainly don't want anyone to get hurt, let it burn and stay clear.

[Fishtail]

Well, my legal training is limited to old episodes of Matlock but I'd probably hem and haw a bit when it came time to discuss this incident with your insurance company.

You might even have a flashback and suddenly recall that you saw two hoodie-wearing youths throw something on top of your refrigerator and under further hypnosis you might even recall hearing one of them say to the other as they ran away, "Let's get out of here before that firebomb we made of old gunpowder ignites and causes a fire in the garage of that completely innocent man we don't even know."

[OH Osthaus]

Originally Posted by greg conomos

Well, my legal training is limited to old episodes of Matlock but I'd probably hem and haw a bit when it came time to discuss this incident with your insurance company.

You might even have a flashback and suddenly recall that you saw two hoodie-wearing youths throw something on top of your refrigerator and under further hypnosis you might even recall hearing one of them say to the other as they ran away, "Let's get out of here before that firebomb we made of old gunpowder ignites and causes a fire in the garage of that completely innocent man we don't even know."

and if I walked up to any official and said I have a hundred pounds of gun powder at my house, the state police critical response team would have me face down in the lawn before you could say second amendment

[Fishtail]

Yep!

When we were teenagers we accidentally set a rather large grass fire in the middle of a very dry spell in Texas by playing with firecrackers. It drew many fire trucks and took a few hours to get under control. Once the fire officials had time to question us, we assured them that we had noticed some broken glass in the ashes and offered our hypothesis that the sun's rays had passed through the glass and the magnifying effect had ignited the blaze.

Now, I'm quite sure the firemen knew we were lying through our teeth. But, they also seemed to appreciate that we were doing our part to help them explain the blaze in a manner which would minimize their paperwork back at the station and keep them from becoming entangled with the dreary workings of the county prosecutor. One hand washes the other, as it were.

[Leighton Stallones]

Tell us about the powder and temperature that caused the fire.
I just checked my 4198 from the 1940's-50's and it smelled fine and I store it in my garage workshop. How old was your powder??

[Elk Hunter]

Originally Posted by Leighton Stallones

Tell us about the powder and temperature that caused the fire.
I just checked my 4198 from the 1940's-50's and it smelled fine and I store it in my garage workshop. How old was your powder??

The powder was WW-2 government surplus 4831 as was sold in the 60's and 70's. The powder was at least 70 years old. I bought it from a friend a few years ago. At the time I bought it it was fine. I checked it a month or so back and it was going bad. You will know when you smell bad powder, it has a strong acid smell. I removed the two gallon jugs of it from my powder storage, an old upright freezer, and put it on top of that freezer. The freezer was outside by the back door to my shop/garage. I was going to spread it on my lawn as fertilizer and had a five gallon bucket that I was going to put it in and then fill with water. The day/evening it cooked off was hot and dry. The powder ignited and then a gallon of WD-40 setting next to it exploded and that alerted the neighbors who called the fire department, one even hopped the fence and tried to put the fire out with our watering hose.

Apparently small amounts of powder that are decomposing don't generate enough heat to spontaneously ignite as I haven't ever read anything about old cartridges igniting. I've had several one pound cans go bad over the years and never had a problem but, I didn't let them sit around when I found they were going bad. In this case there was something like eight pounds in each of the jugs. The large amount and the hot day was enough for it to cook off.

[Leighton Stallones]

Fortunately I have shot up all my old WW2 .50/ lb 4831.