Hi Jeweler.
I am just old enough to have worked and talked to men who earned a living working in the Birmingham gun industry and some of them could remember working in the 1920s browning barrels and of course my ears pricked up right away. The sum of what information I could write down besides a few ancient recipes for browning solutions which I have never tried was this, Browning barrels according to them was more an art form “all muck and magic” and not just an industrial process like bluing, in fact bluing was a far easier. This is my personal view on the subject of the definition change on Damascus barrels,is some older methods increased the definition between Iron and Steel by using Tannic Acid or Gallic acid on the barrels first then the normal rust browning solution. Now I do have a gun that was finished in this way some forty years ago and at first it was stunning but now it is just a rather flat brown colour with far less definition caused I am sure by the passage of time. And I feel sure that cleaning the barrels will do very little to improve matters it is all in how the finish was first formed.
Damascus