Sorry fellas. No footage. I guess I didn't saturate the patches enough or something. Maybe it was a trace of CLP in the bore from the last cleaning. That bore took awhile to come clean, and I had to use a bronze bore brush.
I had shot 10 or 20 smokeless, followed by the 5 black, followed by about 20 more smokeless. I used some MPro7 cleaner moistened, not saturated, patches, followed by a bore brush, and then more wet and dry patches until it was clean to my liking. I probably should have cleaned it at the range, but it was a couple hours later at home when it was cleaned.
There were a few flecks of silver, but nothing soldered into the bore or anything. If I had only shot smokeless I wouldn't have cared so much, but didn't want any corrosion. The lifter had some black powder residue, and the cases showed signs of not really sealing the chamber all that well. Last patch was an oily patch with soiled-diaper smelling Ballistol. Perhaps it mixes better with my beeswax/crisco/olive oil lube than CLP.
In all it was a nice experiment, but I don't believe I'll repeat it. Perhaps a dedicated 44-40 would be a good choice. I guess I'll save my black powder loading for 45-70.
Although... perhaps a duplex load...
I reckon the pressures won't be an issue, say 5 grains 2400 and the remainder black powder? Might seal the chamber a bit better... I can see another experiment looming on the horizon.