Smooth bore nozzle with adjustable bore

A firefighting nozzle of the present invention includes a nozzle body with an inlet and an outlet, a passageway having a smooth bore extending between the inlet and the outlet of the nozzle body, and a compressible member defining at least a portion of the passageway. The compressible member has an inner dimension transverse to the longitudinal central axis. The nozzle also includes an adjuster mounted about the compressible member for selectively compressing the compressible member, wherein the pressure of the fluid flowing into the nozzle applies an outwardly directed pressure on the compressible member to thereby increase the inner dimension of the compressible member, and with at least a portion of the pressure being diverted from the passageway for applying an inwardly directed pressure on the compressible member to thereby at least reduce the force needed to be applied by the adjuster to counter-act the outwardly directed pressure when adjusting the flow rate of the nozzle.