Sam,
Depends on the shot load's weight & type [lead or non toxic], but the Estate hulls I'm familiar w/are all straight walled hulls, so the appropriate wads for best fit will be of that type, i.e., have a slightly larger dia. cup to closely fit the hull's inside diameter. That's the first factor, the second is getting the correct 'stack height' and that is generally achieved with a wad of a specific crush section length and the cup's construction. Long answer, but you asked.
Short answer is check the powder mfg.'s loading manuals; some list loads specifically for Estate hulls.
