clearing bis ex or rav ex at this point in time is kind of a waste of your time. youre to late. within 13 days EVERYONE who is not stupid will buy the i200 eso weapon which outclasses rav ex weapons and makes both ex modes entirely useless except for future unlocking content. so farming rav ex is only useful until basicly next week. if youre still on bismarck by now chances are very small youll be able to get rav done 10 times before the i200 is available.