1914 write-up re: the sideplate IJ
https://books.google.com/books?id=tpY7AQAAMAAJ&pg=PA1062&lpg

The sideplated IJ had monobloc barrels and were marked 'Hercules Smokeless' on the rib, with the W.O. Barnes patents March-16-1915 (No. 1,142,934 for the floor plate action) and April-27-1915 (No. 1,137,045) for the lock-up)

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Some 1892 Ptd. Pieper Eclipse Gun Co. barrels were marked 'Hercules Compressed Steel'
From L' Armureire Liegeoise W.J. Jeffery & Co. c. 1904-1914 sourced "Herakles (Hercules) Compound Gun Barrel Steel" from Canons Delcour

It may be the IJ 'Hercules' refers to the barrel source?

The Hercules Grade was not introduced until 1924 and so marked on the L barrel

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