One in a billion chance

[JSnover]

That 20mm cannon round - sounds like it landed nose first on its contact fuze. Sad to hear of it.

I'd believe that. Spent 20MM cases don't have normal firing pin strikes on their primers, just a tiny pin prick because the M61 is electrically fired; current passes through the firing pin to the primer.
The primer consists of an open-ended brass cup that contains a brass button insulated from the cup by a plastic liner. The firing pin of the gun contacts this button. The ignition charge (a conductive explosive mixture) is in contact with the other side of the button, and is retained by a paper disk and a metal support cup. The electrically initiated primer ignites the propellant charge. The primer explosive element is sensitive to electromagnetic and electrostatic energy.
I suppose it could have been set off by static discharge.

[oldred]

Fellas skeptical or not and no matter what the "odds" it definitely can happen, I didn't just make up that incident about the 12 ga shell, call me and the others liars if you like but it DID happen just the way I described and if you don't want to believe it that's your problem but you are dead WRONG!

[abunaitoo]

I guess it's not as uncommon as I thought.
It's the first I've heard of it happening.
When we were young, we used to get a 12GA round.
Hot glue a cork, with a nail poked in it, so the point would hit the primer.
Hot glue some string or strip of cloth to the other end.
Throw it high in the air, and run.
Thinking back, it was not a very smart thing to do.
No one ever got hurt.
I'll have to try the straw .22.

[Winger Ed.]

I'll have to try the straw .22.

I'd bore out the end of an arrow, and put the .22 in there.

It should make a great 'hold my beer, and watch this' moment.

[Mica_Hiebert]

Any details on that testing, or where to find it? Might be interesting reading.

I wish I could provide that, I work for a large manufacturer and the testing was performed in house by our health & safety department engineers to establish a threshold of how far a loaded round can be dropped accidently and to implement things like load machine heights and to educate employees on the dangers of dropped rounds. In training the example given was a 45acp dropped at 4 feet can discharge.

[Leadmad]

I was going to a shoot and put a 1 gallon bucket with lid on full of shotshells on the tray of my pickup, grabbed something else and knocked the bucket onto the ground heard a bang and the lid came off , one of the primers must have hit an edge on another shell when the bucket bumped onto the ground, the case was split open and just lucky I guess some of the others didn't go off

[Lloyd Smale]

shouldn't say anything because I wasn't there but id bet a dime to a hundred bucks it was a cover up for an accidental discharge. Guy probably wasn't using a 700 rem so couldn't use that excuse. Don't know how many rounds ive dropped in my life but it has to be many hundreds and ive yet to have one go off. Had some that didn't even want to go off with a firing pin hit

[Thumbcocker]

Some years back I had a ziplock bag of .45 colt loads in my loading area. I heard a bang and went to check. The bag had fallen to the floor and one cartridge rim had hit the primer of another round. That round had split the case and a piece of the case had hit the plastic bucket I used to water the dogs. The piece of case had penetrated the bucket. The primer had a crescent shaped indentation from the other case rim. I posted pics on this site showing the pieces of the case.

[nicholst55]

The Air Force Security Forces had a documented and well investigated incident when I was in the sandbox. An Airman dropped a carrying bag containing 800 rounds of linked 7.62mm NATO ammo, and one round fired. I don't recall if they ever determined whether the primer was struck by the tip of another round, or if it landed on something on the ground. At any rate, they had to begin carrying the ammo in the ammo cans which added a bunch of weight to the bag.

[abunaitoo]

Got a little more information on this.
It happened at the range.
Caliber was a 6.5 Creedmore. Factory ammo.
It rolled off the bench, under 3 feet.
No one got hurt. No damage to anything.

[dansedgli]

This happened at my club a about a month ago.

A guy ejected a 9mm round from his gun during unload and show clear. When it hit the ground it went off, it was loose gravel so the primer probably hit a stone.

The split open case ended up about 5 metres behind him, we couldn't find the projectile. No injuries or anything.

[cas]

That was discussed on the Enos forums too. I don't recall any of the reloaders there (and there are a lot) reporting a detonation from tumbling live rounds.

Lee Jurras told us every single round of Super Vel ammo sold was tumbled loaded. In cement mixers IIRC.

I've heard stories a couple times of empties or other objects landing in bu;k ammo cans and setting a round off.

[redriverhunter]

Now I am think of a way to drop a round and keep the primer down thought of a tube but could cause the bullet to get some go don't know have not tried it. I think myth buster is over but it would be a good one for them to try.