I agree with the others that are saying, No bore butter with sabots.
Bore butter has been great for my patched roundball rifle and a lubed felt wad over the powder helped too.
In an inline with a sabot you're squeegeeing all the lube down into the powder.
Shoot with a clean dry bore.
A little resistance from the sabot to the bore helps the powder burn consistently. A Too loose or slippery bullet fit hasn't worked at all for my rifles.

"Camping places fix themselves in your mind as if you had spent long periods of your life in them.
You will remember a curve of your wagon track in the grass of the plain like the features of a friend."
Isak Dinesen