doublegunshop.com - home Forums General Discussion German & Austrian Sporting Guns @ doublegunshop.com 9.3mm x 72mm R - CAST SLUGS (PROJECTILE) SOURCE

Ron,
If I remember correctly the die is threaded 1/2"-20, so you should be able to use a common 1/2-20 bolt to make your expander. An old machinist trick to make a threaded item "run true" is to turn a threading die onto the thread and then "chuck" the threading die in the lathe. Since threading dies(not rethreading dies) are split, they will close on the thread( when the chuck is tightened) and keep the bolt from unscrewing itself.
Mike

If you have an inexpensive Lee universal expander, you could consider making m-style expanders for it instead of the Lyman body. Places like NOE molds and Track of the Wolf have pictures of and sell expanders for the Lee die body. Maybe, an easier project since you don't have to internal thread and keep the outside concentric. They are so basic, but inexpensive at totw that a person might just start with an oversized one instead of round bar stock. Once you setup to make the expanders for either die body, you might make extras a thousanth over and under sized to tweak you loads if the neck tension changes for a bunch of possible reasons. Best of luck with it.

edit to add, I noticed Mike's comment, and I thinks it's spot on for making that style of expander, create a jig that's quick and easy to true to hold your work.

Bullet selection for .358 bullets is sure more comprehensive than for 9,3...you are lucky to have lots of choices.