Abstract: A moisture seal is designed for a shotshell having a biaxially oriented plastic tubular body. The seal is a composite of a thermally conductive layer and a thermoplastic such as high density polyethylene laminated together. The rim portion of the inner layer of high density polyethylene is bonded or fused to the tubular body to seal the shot load end without destroying the biaxial orientation of the tubular body adjacent the rim portion. The moisture seal may be installed inside the tubular body and fused to the inside surface of the tubular wall or may be installed in place of or over the end closure and fused to the outside surface of the tubular body.