Pierre - from granules to dust detonations?

[Rusty S]

Pierre's post enhanced a suspicion of mine.

Years ago I found a polymer tackle box with 10 compartments dimensioned just right to hold 9 HKS speedloaders filled with FBI 38Spl
+P LHP's ( the latch took up enough of the other compartment it would only work with a Safariland speedloader ). It rode under the truck seat year after year. Summer heat that melted the lube, and Winter sub-zero temps. It's still there.

I've always suspected that constant vibration would turn ball or extruded powders ( some of which have surface coatings ) from carefully sized and shaped to contol burning rate granules into dust like flour. So we should be hearing about grampa's 38 blowing to smithereens when shot with ammo in the trunk for ten years right?

I read gunzines constantly, but the only detonations I hear about are with smaller, i.e. less than 75% of case capacity loads of sloooow burning rate powders in humongous cases ( you know them, the idiots that fireform their set back shouldered 6.5 Weatherby-Wright-Hoyer with a half-full case
of powder reclaimed from 50 BMG rounds ).
Yeah, that's hyperbole, but that's what I hear about when you hear about a detonation or sometimes it's called a flashover.

Anyone know of overpressures resulting from shook to death rifle or pistol cartridges?

 

[Hal]

I've read more than a few posts about tumbling loaded rounds. Don't have the desire to do it myself, but since the posters are still around to talk about it, it makes me wonder about vibration breaking down the structure of the powder. Pierre's post, with a thankfully happy ending, isn't anything to dismiss as far as what happened and as to why it happened. I do wonder if the rounds were original, or if they had been reloaded at some point. Since it's impossible to say at this point, I believe the correct approach is to not shoot anything you are not positive of the origin of. Who knows for sure? I mean you are dealing with a substance, that in liquid form, can go off just because the day of the week has a vowel in it. I may be overly anal about it, but I tend to give a wide berth to surplus ammo no matter how attractive the price. Same goes for reloads. I buy a few from time to time at guns shows, but I usually find the guy that shoots what he sells, has all his digits, and has been to the shows for a couple of years. It may be a factor (vibration), may not, but I like to play it safe where pressures like those in a chamber are involved. The only way to equate the condition of the powder of the rounds in question, would be to compare them to a known batch of the same lot, stored in optimal conditions. Pretty much impossible to do. No way, no how do I disbelieve what happened, BUT I would like to hear a complete rundown of all the facts involved. For the time being, I WILL take it as a heads up to check any ammo I use.

[This message has been edited by RAE (edited January 15, 2000).]

 

[Pierre]

Guys, you should understand that I'm not saying that the deteriorated powder was the pointed culprit! The powder in it's state contributed to the incident with higher than normal chamber pressures, but the bolt not going into full battery and the higher than normal chamber pressures caused the events.

 

[Hal]

Pierre,
First an apology if my post was taken in any way other than a kind of out loud thinking way. It is entirely possible that things just came together for all the wrong reasons, as I suspect it did. Sometimes it happens. It is however a point to consider, and I feel that discussion of the topic has merit. I can see both sides of the issue, people tumbling loaded rounds and powder disintegrating(sp) or degradeing into a state other than intended. I would like to see the powder mfgs do a study on it and release the info.