Thanks for the info Richard. I have read that before, when I was following your cartridge conversions.
My concern would be, how well does the Lee Liquid work with black powder? Will it keep the fouling nice and soft? I know that SPG works perfectly with black powder. It kept my Winchester lubed even after 70 rounds of BP loads. It literally took me 5 minutes to clean the barrel after firing, with nothing more than water and Balistol. I didn't clean it until the next day, and the fouling was soft and juicy. It wiped right out of the bore.