This listing was apparently in the 1904 - 1914 W.J. Jeffery & Co. catalog, courtesy of Boyd Taylor Thompson



From L' Armureire Liegeoise Jeffery sourced "Herakles (Hercules) Compound Gun Barrel Steel" from Canons Delcour
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=387087

Canons Delcour likely sourced the Siemens-Martin steel from Acier Cockerill Manufacture Liegoise, which was the source of the "rough forged tubes" used by the U.S. double gun makers.
I've analyzed a Pieper "Eclipse" barrel (Pieper used Cockerill steel) and it was non-standard (high phosphorus) AISI 1030 with a tensile strength of 99,500 psi. Typical pre-WWI "Belgian Fluid Steel".


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