Shotgun blow up


#1

shotgunworld.com/bbs/viewtop … 2&t=268671

I wouldn’t normally post things like this on here but this one makes your eyes water. And its ammo related.

I don’t know how you could blow a shotgun up that comprehensively even if you tried. For a chamber to blow like that is pretty spectacular. Its only maybe a double charge that could do it. Even then they don’t usually go like that.


#2

An un-noticed double propellant charge is unlikely. A double charge won’t allow crimping and is usually easily detectable. Obstruction of the barrel is possible, but not so likely on a skeet range. Maybe the old thing about a .410 gauge shell in a 20 gauge barrel?


#3

The bendy legs on some plastic wads do allow double charges in a way that the traditional felt wads would not. There are x-ray images around of double charged cartridges. I suspect the cartridges were created specially to prove the point that it could be possible. I don’t think any reloader is very likely to have it happen unnoticed.

Even then I am not convinced, the powder burns progressively so the effect of a double charge is not immediate at the moment the trigger is pulled. It would be a buildup in pressure that just continues to build. However, while that is happening the shot would be starting its journey down the bore so more than just the chamber that received the excess pressure.

Shotgun chambers are generally thicker metal than the rest of the barrel so for it to let go so specifically at that one point without any bulging visible further along is strange.

The idea of a .410 or similar stuck in the cone of the chamber does look more likely except that the narrative implies it happened during a skeet session. I don’t know, its more of a mystery than first meets the eye.


#4

One thing for certain I know…the shooter would have soiled ones pants :(


#5

Maybe correct powder weight but wrong powder type.

I have seen some 12 gauge barrels with a 20 gauge cartridge stuck inside that didn’t blew up in that way. the 12 gauge blew out the obstruction and the only damage was a “bubble” where the 20 gauge round was


#6

The bubble you describe is a ring bulge and it would be more or less what I would expect. Shotgun barrels are thin but the pressures are low so it looks like a water pipe that has frozen and bulged, letting go at the outer limit of the bulge . I have seen quite a few. Thats not what has happened here. the destruction is massive and has taken out the chamber totally but left the barrel unbulged but bent and twisted out of shape. That indicates a pressure surge many times greater. It has even fractured the stock right down and taken the top barrel away completely.

Wrong powder type - maybe again, but shotguns use some of the fastest powders available anyway so the margin for error while quite possibly destructive would not be totally massive and so localised. Its a mystery because a strong gun like a Miroku would hold togeather a lot better than that even if it failed.

My only conclusion is that the blowup was staged rater than genuine but the narrative suggests otherwise.


#7

I agree - there is something missing in the story. As you said, shotgun powder (at least for trap and skeet loads) is fairly fast burning already, and unless a charge of something like blank fire powder was used instead of Green Dot, etc. typical of 20 ga load use, I wouldn’t expect anywhere near the barrel damage shown from either a double charge or a barrel obstruction (unless it was maybe a solid steel plug welded into the barrel). Another consideration is that a 20 ga barrel will withstand a higher chamber pressure to reach ultimate metal yield than a 12 gauge having the same chamber wall thickness due to its smaller diameter.

I couldn’t rule out a case of deliberate sabotage.


#8

when you shoot a mortar propelling shell you can have such problems!
the french ones are impossible to chamber in a shotgun (because of a larger diameter at the base than for a regular shotshell), but some of the British one can chamber because they don’t have this overdiameter;

Same story about industrial shell

JP


#9

Is that possible in the middle of a skeet run? I flagged this one up because felt there were unresolved inconsistancies which I still feel are unresolved.

I have seen a few shotguns that have let go and quite a few more after the event. I still feel that this is sufficiently ammo related to come within the remit of the forum because its clearly something that ammo buffs might consider to be part of the bigger picture.

The fact is, they don’t go like this. If its a mystery, then so be it, but nobody should get the impression that this is a normal blow up .

Shotguns are very safe because of their low pressures and the huge drainpipe of a barrel always provides a safe exit for overloads even if if it may bulge things a bit on the way out.

I think this post has run its course, the subject will have to be consigned to the strange but true file and we will never know.


#10

I would have thought what Vince said about the wide barrel would be true for a mortar propelling cartridge. If a mortar cartridge (and no shot) were fired, wouldn’t the pressure simply be vented down the barrel before being able to do much damage. I may well be wrong here, and will accept a better explanation.


#11

It doesn’t work like that, Falcon

Despite the fact you have an exit it will blown up if the speed the gas volum expand (or the wave expand) is greater than the speed the gas volum can exit.

It is for that the serious manufacturers (French ones and some of the US ones) always make Industrial or Mortar shells with a special oversized part in order of not chamber such a round into a shotgun.
The oversized part could be on the paper base or the shells (for mortar) on on the brass base of the shell (for industrial).

JP