Try looking at the "RCSC Specifications for Structural Joints using High Strength Bolts" (also AISC Steel Construction Manual, 16.2) again, its in there. Try in Section 3.
Rule of thumb, you want the hole being punched to be at least 1/16" bigger than the thickness of the metal up to a point, then you want to be 1/8" bigger after that, unfortunately I don't remember what the thickness is.
Are the cracks radiating outward from the punched hole, or are they following the radius of the holes?