Seffner, FL reloading explosion

[GunsNotPuns]

Hello there. My apologies for the self-promotion but some of you may remember the news stories from last October which reported that a man in Seffner, Florida essentially destroyed his home while reloading ammunition. Since then there have been no follow-up stories.

At any rate, I took it upon myself to contact Hillsborough County to obtain first responder, laboratory and ATF reports to see if initial reports and further investigation would continue to support the thesis that reloading was the cause. I have a video up on my channel looking into it which you can find here:

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[Eagleye]

I am very skeptical about smokeless powder causing such a dramatic explosion.
This is more like an explosion caused by flammable solvent vapors.
I may be all wet, but many years with smokeless powders have allowed me
to observe how they burn/deflagrate under many various conditions. Dave.

 

[GunsNotPuns]

It may have come through in the video but I am not entirely convinced either.

 

[Eagleye]

I had to dispose of 21 lbs of smokeless powder that had started to go acidic.
I put it all in a small firepit outside, [some confinement] and lit it.

Pretty good "WHOOSH" and plenty of flame, but definitely not an explosion.
That 6 lbs of even mixed powder could cause such damage seems unlikely.
I DO know that a pint of gasoline in vapor form would produce such an
effect. Dave.

 

[Ganderite]

I am not an expert. But I do have a lot of experience over the last 60 years, including a stint working with experts doing ammo and explosive research.

My comments, in no particular order:
Mixing powders is ok, if the powders are similar. 4064 and 3031 are similar enough. Lots of good reasons to do this. All you have to do is shake well and then do a load development for the new mixture. And this mixing had nothing to do with the accident.

The container. You got it right. A metal container could promote some pressure, but how could a sealed container ignite? Bear in mind that a cartridge in a rifle is very “sealed” and the powder burns. It does not explode.

6 pounds of powder has a fair amount of energy. It would release it all, instantly, if it detonated. It is not difficult to get a double base powder to detonate. These powders are single base and I would have bet it cannot be done.

I can only recall one incident of powder detonating. 20 pounds of double base shotgun powder went bang when bottom-ignited with a squib. Very, very destructive. Would have destroyed a house.

I believe it is almost impossible to get 4064 to detonate by ordinary ignition, such as a primer or smoking.

But, based on my own experience, it is easier than you think to get it to start burning. I had a powder contaminated rug in the loading room and it caught fire from a drop of molten solder. Almost lost the house. Two fire extinguishers failed. Only water stopped the spread of burning powder on the floor. (No more rug in the shop, and I now sweep up after each session).

I wish the report commented on propane, butane, methane or natural gas. That is easy to ignite and will easily blow out a house.