Models with the Bulky (X) Special Rule take up more space on Transport Models." A Model with the Bulky (X) Special Rule does not use up 1 Point of Transport Capacity when it Embarks on a Model with the Transport Sub-Type. Instead it uses up a number of points of Transport Capacity equal to the value of X attached to eh variant of the Bulky (X) possessed by that Model.
"Models with this Special Rule can make Volley Attacks with other Weapons." The Controlling Player of a Model with this Special Rule treats all Ranged Weapons such a Model has that do not have any variant of the Heavy (X) Special Rule or Ordnance (X) Special Rule as having the Assault Trait.