I am begining to gather parts and info for a rifle I will be building with my Father in Law. I already have a gorgeous piece of Walnut for the stock. I'd like to find a Mauser action that takes case coloring well. He suggests the Argentines are good for this and has experience with them but I have not been able to locate one of these yet. As I understand it, if the metal is too hard it is not a good candidate for case coloring. Is this correct? What other Mauser actions are known for taking case coloring well?