While I shoot black, I use magnum primers and ~60 grains volume. (I believe original specs are for 70grains)under a 480g bullet.
A wax paper wad and a pinch of carded sheep's wool (I used to use cornmeal to fill the space, sometimes a cotton wad)
I'm going to try 5744 come spring .....
-And yes, although I haven't checked in there for some years now, britishmilitaria forums is the fountainhead of info for Snidey