in a 3 shot group, my first two shots are within 2 inches but my 3rd is always a flyer(6 to 8 inches high left). this was with 70,75,and 85 grains of pyrodex(80 completely sucked) now i used a " spit" patch, dry patch, and a lube patch between every shot. could this flyer be due to the barrel temperature between the 1st and 3rd shot?
also after the 3rd shot id walk out to the target(100yrds) and mark my shots between powder charge changes, and the barrel would have some time to cool. thanks for any info.

Get the lube out of the bore.
If that don' t cure it, use that yucky bore butter to fill the hollow cavity on the base of your bullet.

I' m only guessing here because you never did mention what bullet you' re using... for all I know, you could be using a roundball. If you are, drop your grains to 65.

One other note! You should not spit-patch bore buttered bores. Bore butter is not water-soluble/will not absorb water. Whatever your dry patch misses could affect your powder/ignition on following shots.