One other issue, that you need to be aware of with the 1903 Turkish, is that while it is a large ring action, externally, it uses a small ring barrel shank.

This means that while you can rebarrel a Turkish to any of the standard calibres, such as those based on the .30/06 or 8x57 cartridges, you probably shouldn't use any of the magnum cartridges in this action. I have one in .35 Whelan and it works fine but I wouldn't like to put a fatter cartridge case into one!