If your tabak is smoking a bit wet then that'll prevent it from burning to, or nearer, the bottom of the pipe (such as any cob will burn to the bottom - mostly the don't). If your pipe ends up with soggy dottle near the bottom try a less moist tobacco or smoke some half bowls to move the process along. Do you still taste burning pine near bowls end?
Most cob shanks char in after 5-10 bowls.
My last two were stellar in less than 10 bowls. Puff on.
