A suppressor, an integrally suppressed barrel system, and a method for coupling a suppressor to a firearm barrel are provided. In an embodiment, a suppressor is configured to have two distinct fittings, each of which provides a point of contact for coupling with a firearm barrel. The suppressor or integrally suppressed barrel system may comprise an expansion chamber with an expansion chamber baffle and wire mesh to alter the sonic characteristics of a report associated with the discharging of a firearm. In some embodiments, the expansion chamber baffle may be movable, allowing for modification to the sonic properties of a cold bore shot vis-à-vis subsequent shots. The method for coupling the suppressor to the firearm barrel includes engaging first and second threaded portions of the firearm barrel with corresponding threaded inner surfaces of first and second suppressor fittings.