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I am getting my first damascus barrel gun. This prompted a reread of an article from DGJ from Fall of '06 by Sherman Bell that conducted an experiment with old barrels, mostly damascus. The 15 set of barrels that he tested were resilient to over 18k psi of pressure, despite some of them being badly pitted.
I am not trying to advocate high pressures. I see no reason for high pressures unless you look for some significant advantage that you can't get otherwise.
His info, while not to be generalized (although I don't see the point of doing the experiment) raises two questions for me:
1. If the 15 guns that went through the testing, showed undamaged barrels (and they did) it would suggest that we are overconcerned by the damage resulted from the use of modern shells to the old barrels. By his limited testing, damage to the barrels does not happen even at high pressures.
2. If the test is inconclusive, especially for your own particular gun, (unless you put her through the proofing procedure) what good does it do to have a set of barrels proofed? Two high pressure shells will not show what is going to happen on that "n" round when the gun will blow up. As M. McKintosh mentioned in his Technicana, you shoot the gun with all kinds of loads and all of a sudden, it explodes using your regular light clay round.
I am surprised that there is no data bank in regards to predictions of how a set of barrels will behave when newly manufactured or after 50 years of regular use and abuse, being pitted or bulged or in the best shape ever. Maybe there is such a thing, but I am not aware of(like many other things). I think that with this much time and history behind us there would be some gathered knowledge to help you better predict what is going to happen to your barrels when you shoot the gun the "nth" time.
Maybe this knowledge is in the folklore, of the saying that "damascus barrels are bad omen" or other kind of popular housewife tale?
Gentlemen, any hard data to scientifically predict anything in the line of old damascus barrels? or any barrels for that reason?

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You might not blow a Damascus barrel up but you can wreck old actions.

I don't risk my body parts shooting low grade Damascus barreled guns...Higher grade guns have higher grade Damascus barrels. I also stay away from pitted barrels and over honed barrels.

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I realize there are many people who seem to have trouble walking around, from stumbling over "Burst Damascus barrels". However; in some 55 years of being interested in & associated with many others also interested in old classic dbl shotguns, I have yet to be showed a bursted barrrel, which could be definitively stated it burst "Because it was Damascus", Period. I have in this time witnessed a good number of Damascus & Twist bbls being shot on a fairly regular basis, though not high volume targets, with regular "Store Bought" shells. I used to tell people they should not be shooting such shells in their guns & most just laughed at me & kept right on. None of them ever seemed to have reached that Nth shell. All the burst barrels I have personally seen, both steel & damascus, had those tell-tale signs of having had an obstruction. For my Damascus/Twist bbls I try to keep my smokeless load pressures around 7500-8000 psi. I use neither max SAAMI pressures or those super low ones. My use of these guns is strictly for hunting purposes & may entail cold weather & those super low pressures scare me under such conditions, too much danger of leaving something in the bore, most efficient way of bursting a bbl I know of.


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jOe,

I am certain that what you do is good practice. It seems common sense. However, do you base your decision on some existent data or the lack of it?
I don't know the full reports of the Birmingham Proof House tests on damascus barrels from 1890's, but what's reported on Revdocdrew's site shows also that damascus barrels tolerate heavy loads before they fail.

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When it comes to old guns with Damascus barrels the data base is too large and varied...I don't see how any "real data" could be gathered.
It was a nice read but what "real data" was derived from Bells tests ?

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'Zircon' issued a call for damascus barrels for testing 12-05. That thread is lost in internet space with Dave's change in servers, but here's a discussion on the PGCA Forum
http://www.parkergun.org/forums/forum1/1143.html
There was a post here 6-06 that testing was in progress, then nothing. I know Dave M sent him some damascus samples (whoever he is?)
There is a gentleman with the appropriate professional creditials who started sophisticated barrel testing, but was slowed by family medical issues. He is, however, still at it and intends to publish his findings in DGJ.

and the original PGCA discussion after the Bell article
http://www.parkergun.org/forums/forum1/511.html

Last edited by revdocdrew; 04/19/08 09:03 PM.
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Of all the testing I have seen, even the old British proof house tests and the later Russian tests, they are statistically meaningless. Joe is correct in this. The sample is always too small to derive any valid conclusions. My job requires dealing with statistical samples and models, so I have some idea what I am talking about.

I also sent barrels to Zircon, both damascus and fluid. He finally asked me to stop sending them. I would be happy to find out what the damascus barrels were actually composed of. I know we have some historical information, but I would like to see some confirmation.

As far as predictive models, the base data set is too small to be meaningful. For this type of model, you need data extended over time. Consider that in a single year, Belgium alone produced over 156,000 barrels. Extend that over multiple countries, over several decades. Remember you have to gather data on both damascus and fluid. Knowing the individual history of each gun, maker, barrel quality, etc would be mandatory. Certainly you need a way to determine that no blockage was involved in the failures. Other potential failure scenarios would have to be identified, verified and included in the data.

The complexity and required sample size become very large... Finally, who has the facilities, time and money to build and maintain the inevitable database that will be required?

Pete

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2-piper,

Thank you for sharing your 55 years of experience. By what you state it seems that 1000-2000 psi +/- does not matter when a barrel resists to 18k psi without obvious damage and it blows up at 30K psi.

Revdocdrew, thank you for the links provided. Interesting reactions, most of them maybe too enthusiastic based on only two guns trial from 2005.

PeteM,

This is what I am surprised about. The fact that there have been so many guns built over a long period of time, yet no gathered info about safety of their use. We have the numbers and the time period.
I understand that 15 guns may not be a large enough sample to draw a conclusion. How should a study be designed to render valuable, statistically significant data? Is there a place where gun accidents are recorded?

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I'm very certain that arguments concerning samples of statististically meaningful size would have been hardly worth the mention if each and every one of Bell's decrepit and suspect examples had blown on a single proof load. The response if one had burst at say 2/3 proof pressure would have been the extremely unscientific "I told you so; why would anyone think it wouldn't with all that pitting/honing/age!" As to Bell's disclaimer that his tests do not speak to the soundness for use of YOUR damascus gun, he clearly believes that some lawyer-proofing is also necessary.

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On a very subjective level, damascophobia has a strong hold on many of us. I wouldn't suggest that anyone begin shooting damascus without benefit of the (sound) advice of those who have so done and an examination by a competent gunsmith (with some damascus experience). I'm not a noted risktaker but have fired at least a couple hundred rounds thru four damascus doubles (two Lefevers, a Syracuse Arms, and 89 Remington Arms. None of those rounds produced over 7Kpsi average service pressure and the first few were fired by "remote control". The day of the nth round hasn't arrived for me; maybe it will. So, yea, verily I say unto you, there is the hope gained from Bell's articles to suggest that a rabbit's foot and crossed fingers may be enuf to get away with it and tell the tale. Could there be exceptions to a grand generalization such as: These fifteen didn't rupture so most damascus guns are perfectly safe with SAAMI pressure loads or even proof or accidental overloads.[?] Yeh, I'd bet there are. Unfortunately, that's what "Finding out for Myself" means.

jack

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