I would like to add that previously I had used store-bought (hard) .314 bullets, sized down to .309 and lubed with a "hard" lube in my .30 Luger.
These bullets leaded quite a lot, it took half an hour and lots of "elbow grease" to clean the barrel.
With wheelweight bullets (+2% tin) and Saeco, a couple of passes with a patch removed a very small quantity of lead "slivers", so I'm very pleased with the performance. These softer wheelweight bullets were sized to .311, the next bigger size in the Lee lineup of sizer dies. (The bullets were pan-lubed).
The reason for .309 with the store-bought bullets is because they were so hard, maybe they would have leaded less if they were a tighter fit. I have used them all up by now, so I will never know. Normally I use jacketed bullets for this caliber.
Urban