doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Barrel Burst- Beretta 682?

Hi craig,

Have to admit that I'm still leaning toward the latter, a theory that the expanding burst in the lower barrel caused a restriction in the top barrel to where it bulged as well upon discharge, all during the one event. The violence of the burst was enough to break the forearm wood into several flying pieces, damaging the shooter, and the fore-end iron as well. To me, that level of force might jar the top barrel tumbler out of place. I think most of us have seen and/or experienced a shotgun doubling where the first shot with a stout load has set off a too-light sear engagement on the second lockwork for what virtually sounds like a simultaneous discharge. Our photos don't show it, but the damaged bottom barrel did bear upward into the top tube enough to lightly dent it. And if that top barrel did let go either on its own (or as someone suggested, from the shooter unconsciously pulling the trigger as a result of the rupture) that may have resulted in the top tube ring bulge. Either way, without the hulls in hand, it's just conjecture.

I just find it curious that the lower tube tore exactly along the two brazings/welds, etc. that attached the side ribs....and they are not soldered on from all appearances. Thanks for your thoughts.....

Rob

To 2-piper & Dave: Both your replies came in while I was typing & submitting a response to craigd....Good feedback, duly noted, and 'Thanks' for taking the time. As for Wonko,.....well, we all know how that goes.

I think, even without knowing the steel alloy, that barrels today are likely to have around .4% carbon. It would seem that's enough carbon to change the structure of the steel to something that was unintended if it was locally heated like you describe. Most all barrels have a very low rockwell hardness number that most folks would consider annealed. Some alloys will also air harden to some extent, possibly locally. It's only thoughts is all.

I'm certain that there are people here more intelligent than I am, and more knowledgeable in certain topics. I expect too that someday they will get around to posting. {;-)

here's a hard lesson:
Just because you think it doesn't make it real
Just because you believe it doesn't make it true

The twit comments about "seams" are certainly amusing. What part of machined, drawn tubing did you not understand? What with the modern testing methods applied to every barrel blank (and what manufacturer would not avail themselves of that in the litigious 21st Century?) makes it unlikely that there was a fault of some kind in the barrel itself. The Beretta 680 series have always had what appear and feel like thin/light barrels. Not as light as some, but still.... Certainly possible that attaching a rib could cause a problem as no process is without potential problems.
These blowup threads never arrive at any conclusion, they just make supposition after supposition and finally die a quiet death. Always fun but never informative. Too bad the manufacturers can't take an active part and not get sued.

have another day
Dr.WtS

Older Beretta barrels were likely 4140 Chrome Moly.
The AV10, 686 Evo, 692, A400 and others have the mystical "Steelium" which is a Nickel/Chrome/Moly alloy.
No doubt pretty good stuff.

A conclusive diagnosis is only reached following the expenditure of several thousand dollars on a Ballistic Analysis, Failure Analysis, and Metallurgical Study by the experts hired by the personal injury attorney representing the shooter. It takes a reasonable expectation of a significant settlement to make all that worth the time (at $375/hr.) and effort, and if a settlement is reached the agreement will have confidentiality clauses.
The big dollars are in pipeline blow-outs and airplanes falling from the sky, not faulty shotshells or barrel defects.

We have previously discussed the fact that Remington�s experiment with AISI 1140 Modified (with manganese sulfide) did not work out as intended, but most of the settlement money no doubt went to the class action lawyers
Loitz vs. Remington Arms, 1990
http://law.justia.com/cases/illinois/supreme-court/1990/68367-7.html
Garza Class Action
http://www.gunsmoke.com/guns/rem_lawsuit_intro.html

If Rob's friend can provide witnesses willing to attest that he was using loads fresh from the factory box, he should, and likely will, receive compensation.

Wonko
For your information seam in modern steel happens when a bit of "dirt" is poured into a cast steel bar, often continous cast and then rolled from the hot band to the finished product. A .10 round bead of material is flattened and lengthen as the steel is rolled and can result in a seam of "dirt" that is only.0003 thick and two feet long. This then ruptures when force is applied to it (a shot) I have seen this on connecting rods and on .026 stainless. You can't see it on the outside but it fails real quick. I believe the 870&1100 recalls were due to Mn stringers, seams.

Bill

Maybe pictures would help

Sulfide and Manganese Sulfide inclusions
https://books.google.com/books?id=rsdbs92yGs4C&pg=PA103&lpg

Manganese sulfide inclusions as fatigue initiation sites
http://www.chalcogen.ro/367_Sohaciu.pdf
Long but interesting failure analysis not unlike the metallurgical study performed for me by METL on the Remington 1894 barrel burst.

Thank You Bill & Drew. I feel certain this will mean nothing to wonko though, He knows Everything, wants to sound big & important, & doesn't really want to be confused by a few mere facts.

This thread has reminded me of a video that you can watch on YouTube produced by Perazzi. I remembered it from several years ago and watched it again to refresh my memory. It states that Perazzi barrels are manufactured in lots of 60. One barrel out of each lot is destructively tested with hydraulic pressure, to failure. It states that they know exactly where each barrel will fail, apparently from previous data.

We know that Perazzi ribs are still soft soldered onto the barrels. Maybe the possibility of structural change in the steel, at the site of the brazing or welds, is why Perazzi still does this. In this day of advanced welding techniques, I would think technology could be applied to prevent these inclusions, or changes in steel structure at the site of brazing. Apparently so, because Blaser does not solder their ribs, and I do believe Blaser has their act together.

Interesting stuff.

SRH

Waaay more than I understand, but manganese sulfide inclusions apparently can form in 4140, today's standard barrel steel
https://etd.ohiolink.edu/ap/10?0::NO:10:P10_ACCESSION_NUM:case1057696631

I can't provide documentation, but believe most Italian, Remington and Japanese Browning, barrel tubes are proved, using a hydraulic device, by a representative of a batch, not individually. Finished guns are individually proved per CIP requirements.

Interesting image of checking the monobloc joint visually and with US
http://www.fieldandstream.com/photos/gal...y-tour/?image=3

Finished gun "after being proofed and tested for POI"
http://www.fieldandstream.com/photos/gal...-tour/?image=10

I believe I told this story before.

In our machine shop we made a collar with 2 o-ring grooves on the OD. The collar was about 2" in diameter and had a wall thickness of about .200. In the bottom of the o-ring there were flaws visable when the groove was polished to 32rms or better. We knew the parts wouldn't pass customer inspection so we sent the parts out to a lab for independent inspection, and it turned out to be sulfur stringers. These inclusions were not visible on the OD of the part, only in the bottom of the o-ring which was .100 deeper. The stringers were not in all of the parts but we trashed all of them anyway.

About 2 years after that our customer started specifying which mills, machining vendors were allowed to purchase material from. My guess was that they saw the same thing in their in house machine shop.

If these flaws were in a thin walled barrel, I have NO doubt that a failure would occur. Just a thought from the school of hard knocks.