March
S M T W T F S
1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31
Who's Online Now
0 members (), 629 guests, and 3 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums10
Topics38,374
Posts544,014
Members14,391
Most Online1,258
Mar 29th, 2024
Previous Thread
Next Thread
Print Thread
Page 4 of 4 1 2 3 4
Joined: Oct 2019
Posts: 452
Likes: 174
Sidelock
Offline
Sidelock

Joined: Oct 2019
Posts: 452
Likes: 174
Thanks, Doc.


Speude Bradeos
1 member likes this: Drew Hause
Joined: Aug 2018
Posts: 104
Likes: 23
Sidelock
*
Offline
Sidelock
*

Joined: Aug 2018
Posts: 104
Likes: 23
The testing by Capt C. Askins and Sweeley, along with De Pont progressive powder and help
from John Olin at Western Cartridge; eventually resulted in some powerful Super-X shells.
The research eventually culminated in 3 in magnum shells and the AH Fox HE Grade Super Fox along
with the LC Smith Long Range shotguns.

The wall thickness and pressure-related incidents are sobering. Particularly as relating to our 100-yr old
fine American fluid steel barreled shotguns. Has anyone or any company done steel metal fatigue testing in older shotguns?
Thanks for the research, DH.

Last edited by 1916XE; 07/17/22 10:57 AM.
Joined: Jan 2006
Posts: 9,398
Likes: 307
Sidelock
***
OP Offline
Sidelock
***

Joined: Jan 2006
Posts: 9,398
Likes: 307
New or vintage shotgun barrels, made with the appropriate steel that is free of defects, do not "fatigue" unless stressed above the yield strength, by loads for which they were not designed, obstruction, or corrosion/pitting.

We have published data from the gun makers regarding yield and tensile strength, and a good collection of actual testing for vintage pattern welded, decarbonized and fluid steel barrels
https://docs.google.com/document/d/1cvqRzkg0wEjhAAcFWr8gFi7aPFRsSIJ_hahfDxmrNAU/edit
https://docs.google.com/document/d/1dnRLZgcuHfx7uFOHvHCUGnGFiLiset-DTTEK8OtPYVA/edit

Joined: May 2008
Posts: 915
Likes: 243
Sidelock
**
Offline
Sidelock
**

Joined: May 2008
Posts: 915
Likes: 243
Drew;

I have often thought about, but do not know, what happens to the structure of the material of shotgun barrels when they are stressed above the yield strength. Would you be so kind as to discuss what the effects of such stress does to the metal as well as the future life of the barrels after they have seen such stress above the yield strength.

Kindest Regards;
Stephen Howell

Joined: Jan 2006
Posts: 9,398
Likes: 307
Sidelock
***
OP Offline
Sidelock
***

Joined: Jan 2006
Posts: 9,398
Likes: 307
I'm not a metallurgical or mechanical engineer, and only know what those that are tell me, and what I've learned from reading.

The non-deep thinkin' non-expert version:
Cleavage occurs when the pressure exceeds the ultimate (tensile) strength of the steel.
Low cycle fatigue occurs when the pressure exceeds the yield strength (or elastic limit; the stress which gives a permanent deformation of 0.2%) and it has a characteristic micrographic appearance described as "wave in the sand" or "beach marks".
The barrel wall stretches (elastic deformation) with each pressure event (shot) until cleavage occurs. The number of cycles required for cleavage depend on the pressure, steel yield strength and ductility (% elongation), and wall thickness...and no doubt a lot of other things I don't understand.
The wall of a barrel that ruptures from an obstruction will of course "stretch" until cleavage (with a characteristic "ring bulge"), and this is not low cycle fatigue.

600X Scanning Electron Micrograph

[Linked Image from photos.smugmug.com]

Page 4 of 4 1 2 3 4

Link Copied to Clipboard

doublegunshop.com home | Welcome | Sponsors & Advertisers | DoubleGun Rack | Doublegun Book Rack

Order or request info | Other Useful Information

Updated every minute of everyday!


Copyright (c) 1993 - 2024 doublegunshop.com. All rights reserved. doublegunshop.com - Bloomfield, NY 14469. USA These materials are provided by doublegunshop.com as a service to its customers and may be used for informational purposes only. doublegunshop.com assumes no responsibility for errors or omissions in these materials. THESE MATERIALS ARE PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANT-ABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. doublegunshop.com further does not warrant the accuracy or completeness of the information, text, graphics, links or other items contained within these materials. doublegunshop.com shall not be liable for any special, indirect, incidental, or consequential damages, including without limitation, lost revenues or lost profits, which may result from the use of these materials. doublegunshop.com may make changes to these materials, or to the products described therein, at any time without notice. doublegunshop.com makes no commitment to update the information contained herein. This is a public un-moderated forum participate at your own risk.

Note: The posting of Copyrighted material on this forum is prohibited without prior written consent of the Copyright holder. For specifics on Copyright Law and restrictions refer to: http://www.copyright.gov/laws/ - doublegunshop.com will not monitor nor will they be held liable for copyright violations presented on the BBS which is an open and un-moderated public forum.

Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.0.33-0+deb9u11+hw1 Page Time: 2.386s Queries: 27 (0.039s) Memory: 0.8159 MB (Peak: 1.8987 MB) Data Comp: Off Server Time: 2024-03-29 07:02:51 UTC
Valid HTML 5 and Valid CSS