Winter, 2005 Double Gun Journal, "The Ubiquitous Ithaca Doubles" By W. R. Hammond, details the use with heavy loads (abuse) of a Nitro Special, fed 4000 or so magnum and short magnum loads over 12 years as the author's duck gun. The gun was very worn when purchased for this use, and had a .003 brass shim installed on the hook to bring it on face. It was then sold to someone who did more of the same with it.
Not beauty contestants, but, they seem to work most of the time.

Best,
Ted