I've been dealing with weapons for large sized creatures a lot lately and I can't find a definitive listing for damage progression for weapons that are large and greater.
Where would I go to find such a list? Should I still be using the old 3.5 chart?
Not sure about sizes beyond Large, but look for "Table: Tiny and Large Weapon Damage" on the Equipment page of the PRD for Large weapons. I believe you generally just start adding another d6 (or d8) once you get beyond Large.