I am highly confident that the bar stock for making the tubes was sourced from Guß-Stahl-Fabrik Carl Berger & Compagnie.

Axel E. on Berger & Colt Peacemaker steel...... - GußStahl:

>>The Gusstahlfabrik (cast steel factory) Carl Berger&Co, later Gusstahlwerk Witten AG, then led by Carl's son Louis Constans Berger, in the 1860s pioneered the use of barrel steel. Besides providing the steel for the Dreyse needlerifles of the Franco-German war of 1870-71, they exported lots of barrel steel to the USA in the early 1870s. Among these exports were large amounts of special-order, large diameter round stock. Their main American customer was Colt in Hartford. So your "all American" Colt Peacemaker most likely has a barrel and cylinder made of Witten steel!<<

https://www.doublegunshop.com/forum...ords=Monopole&Search=true#Post212298

Serbus,

Raimey
rse