I make small game rounds for my hunting rifles. I use smokeless, and I use cast bullets, but not lubed normally.
Years ago a new gunwriter, named Venturino, wrote an article about using TEFLON gasfitters tape wrapped around the bullet. The Teflon proved excellent lubrication, and solved a problem that NRA researchers had long identified, that copper jacketed fouling did NOT play well with fouling from the ALOX based lube used with most cast bullets. This required thorough barrel cleaning when switching from cast to jacketed rounds. OK for midrange target use, but impractical when small game offered tasty camp meat. The DIY plumbers tape found in hardware store is a bit flimsy. Talk to a gas fitting professional for a source.
The next thing for small game rounds is find a medium pistol/shotgun powder in the speed range from Greendot to HERCO. Universal is a good choice. For .30-30. I use 7 to 9 grains while for .308 to 7 x 57, I go up to about 11 grains. While fillers are controversial, I use a quarter sheet of toilet paper or a pinch of soft toy stuffing to hold the powder against the primer.
Sighting a scope sighted rifle for regular use with about a 100 to 200 yard zero will shoot these
small game getters LOW at 25 yards. You must spend some time at the range. A duplex reticle might find using the bottom wire where the dimension changes a useful point of aim with a 4 power setting.
I may be offering information of use only to the experienced cast bullet shooter but it is based on many years of reading the print off THe RIfLEMAN, when the technical writers were among the most experienced authorities in the US. Lou Venturino reaches the same level currently. Use my information responsibly and check other sources. A search term using "cast bullets" and "rifle" is a start. Cascity has some info from The Grand Army of the Frontier. I am comfortable with my years of experience and have enjoyed chomping on grouse potted in trees where legal, and many rabbits.
P.S. I am not recommending black powder in bottle neck cases. Even in the day, necked cases using BP were problematic.