Abstract: Anchoring of a pack-off assembly of an oil well pump is improved by the provision of a tapered conical sleeve as a wedge for a friction seating ring which is forced outwardly against the inner surface of the pump barrel upon advancement of a nut carried on the end of the pack-off assembly. In addition, downward movement of the pack-off assembly in response to fluid pound is limited by the provision of the pump barrel as two separate pieces joined together with a coupling which includes a tapered section slightly reducing the cross section of the barrel but which permits passage of the lower piston by compressing spring-type seals carried by the piston as it passes through the reduced cross section.