I loaded up some Blackhorn 209 for my 45-70 Trapdoor and took it out the other day. I've been using it exclusively for the past few months. My initial loadings were a little light, but I still got pretty good accuracy. I wanted to fine tune the load, so I upped the grains and went with 3 different loadings.
I ran the following:
33 gr. topped with 2 1/8" hard felt wads.
35 gr. topped with 2 1/8" hard felt wads.
37 gr. topped with 1 1/8" hard felt wads.
The boolit was a Accurate 461-405 30-1 alloy, lubed with beeswax, cooking oil and lanolin (55-35-10). I lit it off with a Remington 9 1/2 magnum primer, and the flasholes were drilled out .093 and uniformed with a Lyman flash hole uniformer.
All loads performed very well, with the 37 grain load giving the best group. The target shows the 33 gr load at the top, the 35 grain load in the middle, and the 37 grain load at the bottom. the 33 gr load was about 12" high, 35 gr load was about 13" high, and the 37 gr load was about 14" high @ 50 yds.
All together I shot about 30 rounds through the rifle and never stopped to wipe the barrel. Afterwards I just pushed 3 or 4 patches wetted with TC BP bore cleaner through it until they came out clean. I did my regular routine for cleaning after I got back home.
I used to run 5744 in my Traps, but I couldn't stand the unburned kernels in the bore. 5744 did give some good accuracy, too, and cleanup wasn't bad either. Blackpowder is somewhat hard to find in my area, so I tend to save what I have for my P53, Sniders, and Martini's.
Incidentally, the 37 grain load nearly fills the case leaving room for only one felt wad. Probably a more accurate load that what I can shoot with my old eyes...
Top 33 gr.
Middle 35 gr.
Bottom 37 gr.
37 gr. load close up.