To add a weapon to this category have you got to go to the weapon and place that in his categories. Please do that by the following order: Weapon | (Class) Weapons | (weapon's slot) weapons | Point/Splash damage.
Pages in category "Primary Weapons"
“ The Pencil Pusher is a primary weapon for all classes in Blitz Brigade. This gun has been...
“ The Great Smile is a primary weapon for the Gunner and the Demolisher classes in Blitz Brigade.