Abstract: A caulking gun includes a receptacle for holding a tube of caulk and a handle which has a trigger. A plunger in the receptacle is incrementally advanced by a plunger drive in the handle to push caulking material out a hollow conical snout at a far end of the tube. The trigger has outwardly flared sections or flanges and one of the flanges has a sharpened edge forming a blade. The flanges contact the interior of the handle. To open the snout to dispense caulking material, the snout of the caulking tube is inserted through an opening in a side wall of the handle to the desired depth and angle, the trigger is squeezed, and the blade moves across the opening to sever a tip of the snout and thus create an opening for dispensing the caulking material. The opposing flanges and the elasticity of the handle ensure that the blade maintains contact with the handle around the opening.