Hello, I have played around with paper-patched bullets..and while they can be accurate..it is ALOT of work..and besides..the bore ends up becoming brilliantly polished...but at what point does polish become excessive wear?  So I have kind of taken it easy with this projectile.  Now then, I have these beautiful  .40 Tom Ballard adj. cupped base moulds sitting around getting bored.   Somewhere I picked up a Corbin cannelure tool.  It comes with two .050" and .080" width knurled wheels.  The bullets drop a bit large at .405"dia. with my alloy.  My groove dia. is .408".  I have rolled some lube grooves in these slugs...And if I say so myself..they look darn good!  Nice semi-point profile should fly true way-out there.  I was thinking of using Black..the "kick" of the powder charge should be able to obturate .0015"/side..and they do have cupped base?   
  What do you black-powder experts think?  Have I been sniffing too much Hoppe's?  Thanks Guy's!