One in a Million..ejected case hits open ammo box sets off round

[Im2bent]

 

[Shawn1492]

Wow

 

[iceng]

There is more to this story. Physics don't line up with this. Yes I'm seeing it, but no, I'm saying physics requires more input.

 

[Budrichard]

Elementary Thermodynamics!
Heat set off the primer.

 

[E. Bryant]

Elementary Thermodynamics!
Heat set off the primer.

Please show your work that backs up this claim.

 

[wvfarrier]

What the hell????

 

[Charger442]

48 inch ounces of force needed for a pistol primer ignition right?

I can see it happening but I need to run some calcs on the weight of the spent case and it's curvature to see what point would strike the primer

 

[Budrichard]

https://www.sciencedirect.com/science/article/abs/pii/S0379073810001313

Ir’s not impact that sets off the primer.
Thw above refrence quotes temps of over 300F for ejected brass.
Certainly if you have shot enough rounds out of auto loaders, you have been burned by hot brass.
In the video, The cartridge ejects and as soon as it hits the primer, the primer detonates.
Fulminates will react with temps in the 300F range.
Elementary Thermodynamics!

 

[cas6969]

The odds are high, but it's not something that "never happens". Besides seeing similar things posted about a few times on forums over the years, with "aftermath" pictures, I've been around when it happened. I wasn't standing there, but walked up right after, back when I worked at a range. Ejected round landed in an ammo can with loose ammo in it, setting one off.

If you did a deep dive Googooo search you'd probably come up with a few.

 

[cas6969]

 

[WB300]

No way that brass was hot enough to set off the primer. I've had rounds bake in the sun that were so hot you could barely handle them. That spent pistol brass is NOT that hot.

Now, I have seen someone covering the ejection port while trying to eject a round from the chamber where the primer hit the ejector and set off the round requiring surgery to repair a hand.

My guess is a one in a million shot where the rotation of the brass created enough force when the rim hit the primer to set it off.

Shoot enough pistol ammo around different shooters and you will see some weird shit.

 

[whatsupdoc]

https://www.sciencedirect.com/science/article/abs/pii/S0379073810001313

Ir’s not impact that sets off the primer.
Thw above refrence quotes temps of over 300F for ejected brass.
Certainly if you have shot enough rounds out of auto loaders, you have been burned by hot brass.
In the video, The cartridge ejects and as soon as it hits the primer, the primer detonates.
Fulminates will react with temps in the 300F range.
Elementary Thermodynamics!

Wrong, heat transfer takes time it is not instant.

 

[Skeptic1]

I'm impressed that he was able to talk about it for that long. The man has a gift........

 

[whatsupdoc]

For all you wannabe scientists.

Thermodynamics Heat Transfer - Roymech

Heat Transfer links and formulae

www.roymech.co.uk

 

[culater]

I say it may have been a compromise primer in the seating of it at the factory. It may have gotten crushed when seating and may have made it more sensitive to impact. Just a thought that came to mind

 

[papershredder]

Wrong, heat transfer takes time it is not instant.

Not only that, didn't the industry move away from fulminates to using lead based compounds a few decades ago?

 

[lariat]

Conduction. It is NOT instant in this scenario. Plus the rest of the case is acting as a heat sink. This is means even more time. Heat of the shell is not the culprit.

 

[Average guy]

I remember reading a Clint Smith column about this. He lit one off with a live round dropped in an ammo can I believe

 

[hlee]

Demo ranch posted a video a couple years ago where he jammed 22lr cartridges into soda straws (nose first) then threw them into the air. The asymetric weight insured that they landed on the cartridge rims. They went off when they hit the ground.