Bill:
There was a huge fight over tariffs on rough bored tubes and sporting weapons(Schoverling, Daly & Gales interest) in the late 1800s and early 1900s, pre-WWI, centered on tubes themselves. Makers here fought to keep the tariff as low as possible on sight tubes, "gun barrels rough-bored" - The Hunter Arms Co., the Baker Gun & Forging Co., Parker Bros. Gun Co., Hopkins & Allen Arms Co., A. H. Fox Gun Co., Lefever Arms Co., H. & D. Folsom Arms Co., Ithaca Gun Co., N. R. Davis & Sons, and Harrington & Richardson Arms Co. & others I'm sure.
I believe references can be found in Nov. 30, 1895 Sporting Life
"All gun barrels, whether imported direct from the makers in Belgium, or through an importer in this country(U.S. of A.) to the gun manufacturer, are received in rough tubes, which very much resemble a couple of gas pipes, but being somewhat larger at one end than at the other. These barrels or "tubes" as they are called, are merely tied together in pairs, with small wire and 40 to 50 pairs are packed in a box."
I have a sneaking suspicion Krupp & Sauer teamed up and had the bulk of the Krupp lot that was used by American makers rolled in/near Liege. One of the makers had an exclusive Krupp right. I've read an account or 2 that Krupp tubes upon arrival in the U.S. of A. had the logo of a soldier on them. One exception would have been the Krupp 3 Ringe Special Weapons Grade steel which I'm sure like Whitworth & others had a certificate that accompanied it.
Kind Regards,
Raimey
rse
