There is IMO an excellent write up on "Length of Gun Barrels" in the "Shots from a Greener Gun" from 1927.
I don't have the time to re-type the whole thing but the article starts off addressing "advertisements of a gunsmith who has discovered extraordinary virtues in an exact barrel length of 25 inches, nether more nor less."
To summarize, the article does not denigrate 25 inch barrels but points out that they are no more superior than any other length. It all depends on the individual and the type of hunting/shooting - as to what barrel length is more effective.
