The Brothers Vickers, Albert & Thomas, in the mid 19th century traveled to German to be educated on the latest and greatest in steel technology advances at Neuweidd on the Rhine, or at least Thomas was a recipent. I think it was a decade earlier that Krupp made the reverse trip for the same.

1886 Steel analysis
Vickers #8568 - 0.219% Carbon, 0.529% Manganese, 0.107% Silicon, 0.031% Sulphur, 0.016% Copper

Messieurs C. Cammell & Company - Open Hearth
Messieurs Firth & Sons - Crucible Steel Type
The Royal Gun Factory - Open Hearth
Messieurs Vickers, Sons & Company - Modified Open Hearth??? using German technology???
Sir J. Whitworth & Company - Open Hearth Compressed Fluid Steel forged by a press

Now these were British steel sources for big guns in the 1880s, but I think the sourcing can be extended to small weapons tube forgers like Joseph Kiffin & Thomas Kilby.

Another side note for Bethlehem Steel Company - by the turn of the 20th Century they supplied Nickel steel barrels to Winchester Repeating Arms & Colt's Patent Fire Arms Company

Kind Regards,

Raimey
rse