Guys-- Thanks for the additional suggestions. Heat, I understand-- take more time between shots. I really enjoy this Lancaster and got going rapidly over the course of approx an hour (11 shots). ^^ as noted, felt the barrel heat.
I used just one dry patch and "stuff" came out. However, I think you folks are correct -- more remained. I could feel that the latter balls did not go down as easily -- a little crusty feel. Stuff still in the barrel. Next time out, I'm going to swab more, maybe a little alcohol on a swab and then a couple dry swabs. FWIW-- I'm a real freak for a brite bore at clean up time -- mine shine. But, maybe more attention at the range to the barrel being cleaner is in order.
Thanks for the opinions from the experts.