I think it is more of a barrel issue - the 28 ga barrels on a 20 ga. frame have the outside diameter or a 20 ga (at least at the breach end) and the bore diameter of a 28 ga., which makes for thicker barrels. A scaled frame allows the breach end of the barrels to be smaller in diameter and lighter. My 687EELL weighed more with the 28 ga barrels than with the 20 ga. barrels.

Such a long, long time to be gone, and a short time to be there.