Abstract: Provided is a modular firearm muzzle device having a multi-piece housing assembled from a plurality of substantially tubular, axially assemblable wall members that have a first interior cross-sectional size. A mounting member is mountable to a firearm muzzle. A forward wall has a central passageway that is aligned with the firearm muzzle and has a cross-section size smaller than the first cross-sectional size. The wall members are assembled with the mounting member and forward wall to define an interior chamber through which a projectile passes from the muzzle. The device can be assembled with fewer or more wall members to adjust the length of the interior chamber.