It has been noted in this discussion that American manufacturers often chambered short even though longer hulls were in use. I find this typical hang tag from Parker to be quite informative. Look at the chamber length and then the recommended shell. And these were from the days of thicker paper hulls. Today's plastic hulls are much thinner, offering even less constriction in the forcing cone. For me, I'll go with what the old men suggested. They wanted the hull to open up well inside the forcing cone to provide a better gas seal. Even though today the plastic wad is universal I think the same principle applies.