A clamping device (11) for a multi-part core bundle (12) made of a molding material and to a method for casting using a clamping device of this kind, the clamping device comprising at least one clamping mechanism (16) by means of which the core bundle is subjected to a clamping force on opposite contact surfaces (13) of the core bundle. The clamping mechanism has at least two clamping modules (17) by means of which the clamping force is exerted on the core bundle, the clamping modules each having a clamping element (21) for abutting against one of the contact surfaces of the core bundle, the clamping elements being moveable independently of each other with respect to contact surface.