Lee powder-thru expander problem

[NCHillbilly]

A friend recently bought a Lee breech lock pro progressive press. He tried setting it up today, but with the powder thru expander adjusted per factory msnual, it over expands the cases (9mm). with the expander backed out enough to prevent this, then the powder measure won't fully function. Any of you fellas encounter this?

 

[Western Living]

Yes. This is a shortcoming of expanding and powder charging in one station. The best solution is to expand using an expander die set as desired in a separate die station. Get a short rifle charging die for the powder station to activate the powder drop without expanding the case.

You didn't mention if the powder measure is drum or disk. To try to get the most out of the powder thru expander, be sure the powder measure is not binding due to a drum being tightened too much. If it is loose enough so that it won't bind, you can expect it to leak fine grain powders. Don't torque it to stop the leaking or it will bind. You could attempt to modify the expanding mandrel. This might possibly be worth it if you have a lathe.

Over expanding the case mouth works the brass a little extra, but the bullets should seat easily and a good taper crimp die should close the mouth securely.