Re-barreling question: Why?

[Cosine26]

In the early days of the corrosive primer, the actual cause of rust was not well understood. Many nostrums were created to correct the problem and some, containng water worked. British "SaftiPast" come to mind. Excessive cleaning may have been a cause, since the shooter was directed to clean the rifle diligently for three days after firing. Cleaned with the ineffective nostrums and well oiled, the rifle would appear to be clean and a coating of oil would be applied. The rust would form under the oil. It was not until 1922 that the Huff report provided the real answer and solution. The problem was that the rifle could be cleaned in a dry spell (less than 50% humidity) and would appear to have been cleaned sucessfully. It was then put in storage and a high humidity day would occur and the rifle would rust. Having fired many rounds of corrosive ammo I can tell you that, even with dilligent cleaning, the rifles would develop a "pepery" bore. I always carried a container of water and cleqned my barrels at the end of each day. Many shooters were nor comfortable in using water on firarms though it was quite common in htye black powder days. It was felt by many teams that cleaning the bore caused a change in zero for the first shot. Many teams did not clean their rifles during a multiday match which was fired with "no sighters". Again, I believe that US forces used their rifles mor often than did many of the foreign countries.
With the periodic inspections the barrels would be replaced.
JMO