You probably have been reading some of my threads/posts on 777 pellets lately Big Country. On a high side, you may see an indiviual 50-grain 777 pellet equal to 42 grains 777 loose... on a light side 40 grains because packaged pellets come inconsistent from the Hodgdon factory.

On a another discussion in this thread, Pyrodex is more corrosive than real blackpowder & is also more hygroscopic than blackpowder or even 777.