The Double Gun & Single Shot Journal Finding Out For Myself series by Sherman Bell with technical assistance from Tom Armbrust
Vol 10, Issue 2, Summer 1999, Part 1, p. 9
Vol 10, Issue 4, Winter 1999, p. 21 - Destructive testing of Parker GH Damascus
Vol 16, Issue 2, Summer 2005 - Destructive testing of Parker VH Vulcan Steel
Vol 17, Issue 3, Autumn 2006, p. 12 - Destructive testing 8 Damascus doubles
Vol 17, Issue 4, Winter 2006, p. 28 - Destructive testing 7 Damascus
Vol 18, Issue 1, Spring 2007 -
.....Destructive testing on a Damascus barrel with thinned walls; calculated by O.D. - I.D., not measured
.....Destructive testing using various obstructions, including a 20g shell
.....Destructive testing using a shell loaded with 3 1/4 Drams by volume or 56 grains of Unique
.....(similar to Infallible) with 1 1/4 oz. shot. The chamber burst with the first shot. The 3 1/4 Dram .....Equivalent load is 24 grains of Infallible.
Vol 19, Issue 2, Summer 2008, p. 18 - Destructive testing 1 Damascus, 6 Twist
Vol 20, Issue 3, Autumn 2009, p. 108 - Destructive testing 1 Damascus, 5 Twist
Bottom-Of-The-Barrel Wall-Hangers

The Remington Proof Loads used by Sherman Bell and Tom Armbrust were reported to be 18,560 psi.
Total 28 vintage doubles/54 Twist and Damascus barrels + 2 Vulcan (Fluid) Steel

Good discussion here
http://doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=190599#Post190599

A Parker GH with Damascus barrels and the Parker VH with Vulcan Steel barrels were the subjects of destructive studies in the Double Gun Journal Vol. 10, Issue 4, Winter, 1999, Finding Out For Myself Part II and Vol. 16, Issue 2, Summer 2005, Part IX.
Both guns were subjected to sequentially higher pressure loads at about 2,000 pounds/square inch (psi) increments. The GH testing started at 11,900 psi and one chamber ruptured at 29,620 psi. The VH started with a Proof Load of 18,560 psi. Both chambers bulged at 29,620 psi and ruptured at 31,620 psi.

Here is the Failure Analysis of those Parker GH and Vulcan barrels posted on a public internet forum by 'Zircon' in 2007
http://www.shotgunworld.com/bbs/viewtopic.php?f=5&t=234280&start=20



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