A slug from the very good bore of this Mauser mic's exactly (groove) .325". Can someone recommend a production cast bullet mold (about .326" dia.) for this rifle or would a custom mold be required?

I have the Lee for a Turkish Mauser with a smaller bore but for your larger bore rifle you might try the mould sold thru Midsouth that was designed by a couple of real cast bullet ("boolit") guys. They have one of 2 molds in stock. I just ordered one yesterday.
Good shooting,
Newtire

Newtire...thanks for the lead. The 215g Lee "Karabiner" at .327" looks like it should work fine. Ordered it this morning.
Thanks again...

Jon