I've only broken mine in (Lyman Deerstalker). I haven't tried various things to see what improves it.
SWMBO only allowed me to use the grape seed oil out of the pantry as her olive oil is an expensive one.
I settled on 70 grns of 3F as it made me think of the 45-70 Gov't. Initially I was using the RS and P my father gave me as I hate that powder. I've since moved on to using mostly Olde Eynsford, though I'm certain I've tried Triple 7 as well.
My patches are pillow ticking these days (0.016") and coupled with the .490" balls I cast it takes a small amount of effort on the short starter to get them going.
I found that I need glasses more than I realized. I can see the orange bull at 50 yds but it's not very clear. My groups run from 2-4" or so, and I'm hoping it does better.
I bought some 320 grn Lee REALs mostly to see what recoil was like with a heavy projectile. My first was about a foot left and several inches low, and had keyholed at 50 yds with the typical 70 grn charge. I happened to have wads and tried 2 more and they were nearly touching and just below bull.
Needless to say I bought the mold!
I'm certain with more work I'll find a good load, and I'm hoping to have a <4" group at 100 yds.
I also bought a used 250 grn REAL mold to try.