I lube them with dilute ALOX and when it is close to dry dust them with a mix of motor mica and graphite. They are sized .309 after the lube job and shot from a 12" twist barrel....they don't ever lead the barrel.
I've found that single shot handguns/rifles don't need much skullduggery to keep them from leading. I shot thousands of cast bullets made from straight quench cast wheelweight alloy through a .357 MAX barrel and soon forgot all about the possibility of leading the barrel. My hotter loads were doing 1750 fps and lubed with whatever alox was the cheapest at the time. No leading ever.
My most recent cast bullet experiment was the Martini Cadet shooting plain base commercially cast bullets of an unknown alloy at 1700 fps. I cut them down to 128 grains from 170 grain bullets intended for the 8mm Mauser cartridge. Cutting them down removed all but one lube groove so I painted liquid alox on the bore riding nose of the bullets after they were loaded into the case. No leading
Every so often I would run a dry rag through the barrel to remover the soot and the bore would shine like a new dime.
Revolvers are a different matter. The transition from the cylinder to the forcing cone into the rifling would leave lead streaks in the first 3" of the barrel with the hotter loads made from quench cast WW allow,....especially with plain base bullets. Gas checked bullets were more forgivable.
