Abstract: This invention relates to an improved method and apparatus for use in extruders of the screw type having an elongated passageway defined by a rigid barrel, the surface of which is susceptible to wear from abrasive, corrosive, adhesive or other severe wearing conditions. The improvement comprises a relinable barrel assembly having a housing, a removable sleeve liner and means for securing said liner in said housing. The housing has an elongated tapered bore therethrough, tapering from the feed end to the discharge end of the barrel (i.e. the largest cross-sectional diameter of the bore is at the feed end of the barrel). The sleeve liner has an elongated tapered exterior surface, shaped to mate tightly within the tapered bore of the housing, and an interior surface of wear resistant material, wherein the interior surface defines the passageway within which the screw of the extruder rotates.