A method and instrument is used for inserting a bone screw through a hole in a bone plate into bone at a maximum angulation of a bone screw central longitudinal axis with respect to a central axis of the hole. The maximum angulation places the head of the bone screw at or below an outwardly facing surface of the bone plate. The instrument has a distal end including a gauge element spaced proximally from an end surface of the distal end when in contact with a counterbore surrounding the plate hole a distance less than a depth of the counterbore. The instrument is tilted with respect to a central axis of the bone plate hole to an angle wherein the gauge element remains at or below the outwardly facing surface of the bone plate adjacent the counterbore. A hole is drilled through a guide bore in the instrument.
