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01-09-2021, 10:27 PM | #13 | ||||||
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Just because a good gun can easily withstand a proof load withous suffering any visible or even measurable effect does not mean the gun should be subjected to such stout loads except during a proof test. A particular proof load is about twice, or greater, the recommended max for a gun. I like to stay well below 7,000 psi in any of my guns, even fluid steel barrels. Keeping in mind that the barrels are not the only parts of a gun that undergoes stress every time the gun is fired.
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"I'm a Setter man. Not because I think they're better than the other breeds, but because I'm a romantic - stuck on tradition - and to me, a Setter just "belongs" in the grouse picture." George King, "That's Ruff", 2010 - a timeless classic. |
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01-09-2021, 11:14 PM | #14 | ||||||
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Think I just found the info and the titanic steel barrels are rated to 75000psi when new!
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01-09-2021, 11:23 PM | #15 | ||||||
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I get your point the reason I wanted to know because the way people talk about old guns it is very unnerving and almost put me off buying a good old piece of history.
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01-09-2021, 11:27 PM | #16 | ||||||
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Thanks that’s great info
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01-09-2021, 11:53 PM | #17 | ||||||
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Parker's are not just any "old guns". If you want to see something amazing, see if you can track down the Double Gun Journal article by Sherman Bell called "Finding Out For Myself".
Mr. Bell does pressure tests on old Parker Damascus barreled guns. He uses old rattlely worn out guns, just to make it interesting. Runs blue pill proof loads through them, gradually increasing the pressures of the loads, to see how far they would go before they burst. They went out to 30,000 lbs plus, before showing any signs of stress. For the record, none burst. |
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01-10-2021, 06:47 AM | #18 | |||||||
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Quote:
I’m sure you will find that the 75,000 lbs you refer to is “shear strength” and not distortion or burst pressure. A proof load for Parker fluid steel barels is well under 20,000 psi and should never be subjected to loads of even half of that. Again, I keep all of my loads, even for my Titanic barrels, at less than 7,000 psi and they do everything I ask them to do. .
__________________
"I'm a Setter man. Not because I think they're better than the other breeds, but because I'm a romantic - stuck on tradition - and to me, a Setter just "belongs" in the grouse picture." George King, "That's Ruff", 2010 - a timeless classic. |
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01-10-2021, 08:06 AM | #19 | ||||||
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Perhaps shot-shell manufacturers should refer to their 'low' pressure ammo as ' lower' pressure, but they (and I) probably don't need to know what pressure is necessary to blow up a barrel. It's easy enough to know the range of pressures being offed, and if their's falls on the lower end of the scale, that's all that necessary to legitimately call them low pressure.
Lots of tests have been run on various steels used to make barrels by Parker Brothers. These tests, undertaken by members, and using labs and procedures considered meeting standards such as ANSI, ASTM, ASME, and NAVSEA, were published both here, and in Parker Pages articles. Alloy steels, typically CrMo, and CrNiMo, have UTS (Ultimate Tensile Strength) above 80,000 psi, and most are in the 90-60 range (90,000 UTS, and 60,000 Yield strength) not,"Shear Strength" as stated above. I don't think anyone has ever done extensive testing on composite barrels like that done on steel barrels. In order to do a proper test, samples would be examined both non destructively and destructively. It's pretty hard to say what is "specification" as you're dealing with at least two distinct materials, and in a form which would be difficult to segregate. These materials aren't homogeneous but from a practical standpoint, have to be treated like they are, knowing any test results are pretty random. |
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01-10-2021, 08:14 AM | #20 | ||||||
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Michael, the best information, IMO, to figure out what I think you are trying to determine, is the pressure data for commonly sold shells that were in service during the time the guns were made and used. Much data exists on what those pressures were. Many readily available loadings of the day were in the same range as our modern shells (up in the 10,000 psi range).
A comparison using pressures necessary to cause a gun to fail when new would be useless unless you knew what it would take to cause that same gun, after 100 years of use, to fail. Bell comes the closest, in modern times, to doing that of anybody we know of. But, it's only 100% valid for that particular gun, because of the way condition varies so much with vintage guns. It may, however, be somewhat meaningful for us. Some have graciously posted charts and figures that show the pressures of vintage loadings, and you could probably find them with some searching, or they may read this and repost them. When we call a loading a "lower pressure" load it is usually the result of a personal comparison of the pressure of the load(s) in question with the pressures of the loads of the day. I base that call on the individual gun in question ....... it's condition, and what it was designed to shoot originally. I've loaded and used shells that range anywhere from 5500 - 10,500 psi in my vintage guns, though not all of them were "lower pressure" loads. Remember, higher pressure does not hurt wood on a gun. It only places increased stresses on the action, the lockup and the the barrels. Recoil resulting from a heavy payload, and higher velocities, is what is a detriment to old wood in poor condition. So, what it comes down to is whatever an individual considers "low pressure". If the gun was designed to shoot 10,000 psi commercially loaded shells I personally consider anything from 8500 psi down as being "low pressure". Others would not consider 8500 psi "low", but it certainly is lower. |
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