CJF,
My comment about the 38 Special was directed to SKB, his is chambered for the 360 Rook ( like a shortened 38 spec, but with oversized barrel, similar to some 9.3x72R barrels). If I had yours I would also stay with 360- 2 1/4" Flanged. I have been looking for a 9.3x57R ( metric version of the 360 Express, varying groove diameters) for quite a while.
Mike