In the game you have different classes, each of the classes has a melee weapon and a ranged weapon. Now the Witch hunter class starts off with a rapier as melee and pistols as ranged.
If you block with the rapier it also shows that he is holding a pistol, also his melee weapon has a bullet counter which the rest of the melee weapons don't have.
Now the question is is it possible to fire the pistol while using the rapier as melee?