Hey Kevo,
Not big into the black powder.
Will say this, what you run into is case volume. You can not have any space in the case.
The powder needs to be "compressed".
In the 44-40, the guys around here are favoring the "Swiss" brand.
If you are using regular "black", and the 200 gr bullet, you would be served well by 35 to 40 gr of 2F, and some filler (cream of wheat......etc)
You will also want a "softer" bullet, than you would use with "smokeless".
Just my .02 cents worth.
Later, Mark