In one embodiment, an apparatus for shaping an article may comprise a plurality of movable dies arranged to form a chamber whose size may be varied by moving the dies. Each of the dies may have a contacting surface for contacting the article to be shaped. The chamber may have a first portion having a first cross-section and a second portion having a second cross-section. Either portion may include a taper. The first portion may have a differently shaped cross-section than the second portion. The first portion may have a cross-section of greater area than the second portion. The longitudinal axis of the first portion may be offset from the longitudinal axis of the second portion.