Thank Goahead and Edstainless for your responses. The Mg alloys mentioned earlier are good die casting alloys. However, if used for permanent mold casting, they are not so good. Hot tears, non fills and shrinkages are quite bad. My impressions are that AM50 and AM60 have even worse castability than AZ91. Not sure if this is also experienced by you, and if you did, how did you do to improve the castability? Improved die coating?