My Minotaur is on it's second drill. First drill was over the label, about 5X5.5 with the MB in the track. It got pretty good length with a mellow move on the backend. I decided that I wanted this to be my heavy ball, so I plugged and redrilled 3.5X3 with the MB on the VAL. This ball is now a monster. Huge arcing reaction that never stops hooking.
Point is, with MoRich, you get what you drill. Pay close attention to where you place the MB. 4X4 should be pretty strong under most circumstances.