Source: Epic Level Handbook
While in a rage, you can deal tremendous damage to objects.
Prerequisite: Str 25, Power Attack, Sunder, rage 5/day
Benefit: While in a rage, you ignore the hardness of any object you strike. Also, double your Strength bonus for the purposes of any Strength check made to break an object with sudden force rather than by dealing normal damage (including bursting bindings, such as ropes or manacles).