AD due to static shock?

[Irving]

So I just shocked the crap out of myself (reminding me why I never turn on the light in my office) and I was wondering if anyone knows how much you'd have to shock yourself in order to discharge a round. I know I could have worded that better, but I don't remember if it is watts or amps that would cause this and I'm sure someone will come along and explain it soon anyway.

It seems to me that 1) The gun or round would need to be touching your skin, so most holstered guns wouldn't be an issue. 2) The amount of current it would take going through your body to set off of a round, would probably be more of an issue than the round going off.

Discuss.

[Circuits]

Your first trick would be getting the shock to the powder (effectively impossible in its metal shell), or somehow directing it to the primer (also really hard given it's embedded in a metal chamber, and backed by the metal of the bolt or slide breech face).

If you can get the static discharge to the primer, will it generate enough heat or shock to set it off? Doubtful, given the shock's coming from the cup side... again shielding the sensitive bits from the effects of the spark.

[xjtwo]

Watts is the product of Volts and Amps or Watts is power.

Do you mean to actually ignite the round by electrical shock? Or by handling your firearm while being shocked? This sounds like a job for myth busters.....

It only takes 100 milliamperes (0.1 amps) to put your heart into ventricular fibrillation, meaning your heart is out of rhythm. Course, depending on where the current (amps) goes thru your body might make a difference.

Then there is freezing current which causes muscle contraction and will hold you to the circuit. This happens around 20 milliamperes (0.02 amperes). It only takes a few seconds for blisters to form where the current passes through the high resistance skin. The skin loses its protective resistance & current increases. Someone basically needs to knock you off of the circuit......

[Irving]

Thanks guys, sounds like mythbusters indeed.

They would probably start by directly shocking a round all by itself and seeing what the threshold is, then going from there.

Circuits, I don't know anything about igniting powder or primers (obviously ), so most of my questions are going to sound stupid.
-Can you ignite gun powder from a direct electrical shock in the first place? If so, is it not a function of electricity at all, but just the heat created?
-What is the difference between the primer and the lose powder in the round, in reference to the topic of course?

[Circuits]

Circuits, I don't know anything about igniting powder or primers (obviously ), so most of my questions are going to sound stupid.
-Can you ignite gun powder from a direct electrical shock in the first place? If so, is it not a function of electricity at all, but just the heat created?
-What is the difference between the primer and the lose powder in the round, in reference to the topic of course?

From a technical perspective:

To light up smokeless powder (or any flammable) you need to get enough heat close to a grain of powder for long enough to cause it to ignite. There is a LOT of heat inherent in a spark-gap electrical discharge, but it's very, very localized, and very, very short for a basic static discharge. That "pop" you hear is a mini sonic boom from the air displaced when the discharge flashes a small volume of air to a plasma.

The heat's probably more than enough, but the duration, affected volume and overall energy content of the spark is not enough to raise even a portion of a powder grain to its ignition temperature. If the ambient temperature were very high, it'd be easier, because you'd have the powder grain closer to its flash point. Flash point is the temperature at which the powder will spontaneously combust, with no extra heat input required. By way of example, if you drop a lit match into cold cooking oil (or diesel fuel), it'll go out, because the ability of a small flame to heat the oil on contact isn't enough to raise any portion of the oil to flash point (and release flammable vapors) before the small flame is suffocated by contact with the liquid medium. If you raised the cooking oil to a few degrees below its flash point, then dropping a match in has a good chance of lighting the oil before it goes out. So... doubtful the small spark of a static discharge could raise room-temperature, or even desert-environment-temperature smokeless powder to ignition temp all by itself, even if it could somehow get to the powder through the cartridge case.

Back to how a primer is different - it's a SHOCK sensitive explosive compound. The plasma discharge and supersonic crack of a spark gap discharge occurring are potentially more than enough to set off primer compound, if it gets to the primer compound unobstructed. Once the primer compound explodes, it generates a much larger volume of hot gaseous byproducts, which are then enough to ignite the powder in the cartridge.

Primers would be no good if they were TOO shock sensitive, however, and the primer compound is buffered from the shock of a spark gap discharge from its outside, by the thickness and resilience of the metal in the primer cup. A fat spark discharged into the open end of a cup very well could set off a primer, but I think has about a zero chance of doing so for an installed primer, from the cup end/outside.

There ARE electronically-ignited primers, though they typically use a capacitor discharge, like a camera flash circuit, to boost the duration and temperature of their spark, and insure reliable ignition. If you were to fashion a special spark-sensitive primer for small arms ammunition, it could likely be set off by a fat static spark, or a piezoelectric discharge, like a lighter's, but only if you designed the primer to channel that spark across a gap inside it, and designed the firearm to get that spark into the chamber, to contact it in the first place.

So, in mythbusters fashion, the base idea is BUSTED, because you'll never get a static spark inside a firearm to the primer, or inside the cartridge to the powder, and if you did, unless the primer or something was specially designed to channel that spark inside, it wouldn't do any good.

Onward, in mythbusters fashion, if you wanted to TRY to set off a cartridge with a spark of some sort, then I think you could probably achieve it with a stun gun, contacting the primer, and after a bit, that spark would heat things up enough to maybe set off the primer. Best-case scenario for a try at electrically igniting a handgun round would be to wire a stun gun to the firing pin (insulating it within the channel) so that it'll discharge from its closest point into the primer cup, and then let it rip until the battery runs out or the gun goes off. If that didn't do it, you could replace the contents of the primer with a lower ignition temperature compound, including its own oxidizer, and repeat the experiment to see if the spark can heat the cup enough to ignite its contents, and in turn light off the main powder charge.

FWIW, an electric blasting cap works by explosively detonating a short, thin, length of wire, with a pulse of current, and it's the shockwave (just like that of a static spark discharge) that actually lights off a high explosive, not heat. That's why shooting C4 or dynamite or tannerite will set it off, while setting it on fire by itself will just cause it to burn up slowly.

[Irving]

See how much we all (or maybe just me) learn by asking silly questions? Thanks so much for taking the time to explain all of this stuff Circuits. I (and hopefully others) really appreciate it.

Now, you mentioned C4. I know less about C4 than I do gun powder, but I was under the impression that you could set it on fire, or kick it, drop it, etc, but without the presence of both heat and pressure it won't "go off?"

[SA Friday]

Sure, burn it, kick it, smash it with a hammer... It will burn, but other than that you are ok. Fire a rifle round into it and you may have issues. It's the shock wave that will give you issues not the heat. Not all plastic explosives are the same though. Some are down right sensitive.

I wouldn't recommend handling any explosive as described above. I know there are some of them out that are very impact sensitive, especially detonators. I usually didn't get too exicted when Airmen jostled the box of 1.1, but if they dropped the 1.3's I ran.

[68Charger]

Basically, unless the primer is exposed you'd have to have a shock strong enough to heat the primer/powder to flash point... if it's getting that hot, a round going off is going to be the least of your problems..

since the casing conducts electricity, there would be no spark inside, unless the spark is big enough to blow a hole in the casing.. (welding arc?) which if there is that much energy left after passing through your body, you've got many more injuries than the bullet..

now while reloading, and the powder/primer is exposed? that's another matter- any visible spark is probably enough to detonate.. it won't be contained- so no explosion, but could blind/burn you...

[Marlin]

Yep,, what 68Charger and Circuts said,, If you get enough to discharge some ammo,, It really won't matter,, at least to you.... Unless it's a FPE breaker, it should trip loooooong before that happens anyway..

[rl45acp]

My pop and I essperimeted with this lond ago. I DO NOT RECOMEND TRYING THIS!

We put a little gun powder on a piece of aluminum foil, about 5 grains worth. We ran our feet across the carpet, and touched the Al foil, ZAP! And that was all that happened. We tried this over and over, and nothing but a zap. Then we tried using flash powder (substance used in salute fireworks) thinking that the Bullseye just wasn't volitile enough. Still nothing happened.

I think we had more fun zapping each other, than zapping the powders.

With this said, BE CAREFULL WITH STATIC NEAR YOUR RELOADING BENCH. These were just small amounts of powder, there is no telling what might happen near a pound or more.

As far as an AD, I dont think it could happen, but then again those tazers have quite a ZAP to them.