All of the Hodgdon produced propellants like Pyrodex and 777 have their chemical compositions listed in the associated SDS published on the Hodgdon web site. Dig away!
As an aside, having been shooting BP since the mid 70's and shooting Pyrodex as well when BP isn't available at the LGS, we shooters prefer the substitute to be smelly, dirty, nasty, and blackish so it is a BP substitute. When I don't want to fool with nasty fouling, I bring the modern stuff to the range for a day. Clean-up is quicker and easier.
When I want to hang out with the guys for the afternoon, I shoot BP and/or Pyrodex all morning. Part of the social engagement is the cleaning session afterwards and the associated rotten egg smell of the cleaning area. There is poetry and history in the process. Who has the best cleaning juice? Why did Bill's rifle clean up so fast? All that cleaning commotion is part of the adventure to a lot of us.
Hopefully you also participate in a club style shooting day with a bunch of great guys and gals. It sure is a lot more fun than a day alone at the range with nobody to tell lies to.
I too shoot a 36 Remmy. That is a great revolver to shoot and if you haven't thought of it, a conversion cylinder opens up a whole new chapter with 38 Short Colt and 38 Long Colt ammunition. You can use smokeless for those if you wish but I shoot them with Holy Black too. I sent an article off to the staff to publish in TFS about shooting the 36 Caliber conversion cylinders on the 36 Colts and Remmy. It should be in there within the next few issues.