A method of forming a barrel portion including obtaining a mandrel shaped to define at least an inner surface of a barrel portion of the bat, wrapping a first plurality of layers of fiber composite material about the mandrel, placing a removable material over a first portion of the first plurality of layers, and wrapping a second plurality of layers of fiber composite material over the removable material and the portion of the first plurality of layers not covered by the removable material for form an assembly. The method further includes separating the mandrel from the assembly, inserting an expandable member within the assembly, inserting the assembly into a barrel-forming mold, and molding the assembly in a single molding cycle, curing the first and second layers with the removable material to form the barrel portion of the bat, and removing the removable material and the member from the barrel portion.