doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Blow Up EUREKA

So you picked up on the 'Casablanca' reference, but I bet you had to look up metal-lurgist.

There a Tom Armbrust article I believe on his website floating around on the net that shows about 1500psi swings just on primer swap (different powder on that test). Also, he showed a target load using Clays powder that rose about 1800psi only on depth of crimp changes. There were some folks that thought the original load was on the warm side for the gun, and I was thinking small variances might have been feeding the gun higher pressures than it seemed.

Craig, yes I have also read Tom's reviews and I will agree there is much to know in reloading. I have also seen a powder that just substituting a primer only changed it a few hundred psi.

There is a lot of information on reloading on Shotgunworld in the Reloading section, many have had loads tested and have shared their results. Most all will agree that shooting in the 8,000 psi range, a primer substitution will not bring you close to SAMMI's pressure for 12 gauge which I believe is 11,500 psi.

I do have to agree, that his load was high for a vintage gun no matter if a Damascus or fluid steel barrel.

Damn I missed that. Love that sort of thing.

I don't know what may have caused it, but it looks like a severe over stress of one or few cycles.

The large crystal structure is what I'd expect for Damascus given how its made. I would think a low cycle fatigue failure would show striations.

If you can perform some hoop tensile tests of samples from the barrel just ahead of the failed section, I think it would be very telling. My wild guess is that there was no metal deficiency that caused or significantly contributed to this.

I made a fixture to do this testing a number of years ago and sent it to a member in Oregon.

Who would venture a guess on the pressure this failed at?

Been following these threads with some interest and have to say this is some of the best forensic detective work I've seen in a long, long time. Y'all are to be congratulated and encouraged for it.

Now for my $0.02. I believe the consensus has coalesced around there having been an obstruction in the barrel. I recall part of the early discussion being that there was snow in the area when the gun was dropped after the blowout. Could the obstruction, which seems to have been the cause, have been snow itself?

Getting a clot of snow in the barrels is something I'm always watching out for while hunting in winter conditions. It has happened to me - thankfully I caught it before firing - and I can say it does happen without even noticing it.

Not really- I may not be one, but I know how to spell that word- the AWS Welding Journal and also the Lincoln Electric Co. "Stabilizer" use that word in reference to a welder's need to know the basics of both ferrous and non-ferrous metals identification- ie: spark testing on ferrous metals, etc. There is an old but true saying that a good quality weld depends on 90% proper preparation, and basic knowledge of metallurgy is part and parcel of that. And with that, you can "Knock on wood"- with or without Mr. Dooley Wilson on the "shortened Steinway"!!