An adjustable doff core device for installation in the hollow center of a center-pull doff has a tubular core with a fixed internal diameter configured for engagement on a processor configured to dispense material from the outside of a doff. An adjustable outer press bar portion is adjustably mounted on the outside of the tubular core by an adjustment mechanism and is movable between an inner, contracted position and outwardly expanded positions spaced outwardly from the tubular core to define an adjustable outer diameter of the device. The press bar portion is configured for substantially non-slip engagement with an inner diameter of a hollow center-pull doff. A locking device releasably locks the press bar portion in a selected adjusted position.