Abstract: A firearm suppressor having a core, a first end, a second end, a hollow bore extending along a longitudinal axis from the first to the second end, and an energy management structure. The first end of the suppressor includes a set of threads for connecting the suppressor to a firearm, and the bore includes a plurality of openings into the energy manager. The energy manager includes a plurality of chambers extending from the bore. A method of designing a firearm suppressor including setting a pressure range to be contained by the suppressor, establishing certain manufacturing parameters, choosing a structure for the core, modeling performance values for the core, selecting a geometry of the structure, and selecting a sleeve for the core.