@jetinteriorguy:
The Lyman Multi-expander dies I mentioned in the post before yours has the hollow tips with that same Lyman M profile that NOE and several others have adopted. But I don't know about the compatibility with the Lee die, specifically. The Multi-expander comes with its own die body. This eBay photo shows all the parts. The row on top shows the powder-through expanders. The lower row is a set of adapters for the different expander plug diameters.
The Lyman Multi-expander dies I mentioned in the post before yours has the hollow tips with that same Lyman M profile that NOE and several others have adopted. But I don't know about the compatibility with the Lee die, specifically. The Multi-expander comes with its own die body. This eBay photo shows all the parts. The row on top shows the powder-through expanders. The lower row is a set of adapters for the different expander plug diameters.