If tube matching errors occurring, it originated in Liege. The patterns were paired and wired together 'rough forged' and shipped in a barrel to the U.S. maker. The pattern would be difficult to discern through the finishing, joining and fitting process until colored.
Nov. 30, 1895 Sporting Life
http://www.la84foundation.org/Sports.../SL2610011.pdf
How Shot Guns Are Made and the Process Through Which They Pass Fully Explained
The beginning of the manufacture of a gun is the barrels, and it is generally known that no barrels are made in this country except the rolled steel, which is used on the Winchester gun.
All gun barrels are now imported, although an attempt was made a few years ago to produce them in this country, but with only partial success. England, Germany and Belgium supply most of the barrels, the latter country doubtless producing the larger quantity. All gun barrels, whether imported direct from the makers in Belgium, or through an importer in this country 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.