Well BOLS released the badab war play aid book. Check out the Space sharks assualt rules.

Chapter Tactics: If you include Quintus then all Space Sharks units in your army lose the Combat Tactics special
rule. Instead, all Space Sharks wearing power armor are subject to the Feeding Frenzy: Any close combat attacks
which roll a “6” to hit generate additional attacks which are rolled immediately. Continue rolling until no more “6”s
are rolled.

i wish regualr marines or khrone beskers could have this rule.