An inertial decoupler and suppressor assembly, associated components, and associated methods. The inertial decoupler is adjustable to change a preload of a spring biasing a piston toward an at-rest position and/or to change a permitted travel distance of the piston away from the at-rest position. The inertial decoupler can be removable from the suppressor and usable with other suppressors, or can be integrated with a dedicated suppressor.