I have one of them too. It's a treat to carry, compared to the heavier 1". Mine is equally happy with 90-100 grains of Goex 2f or Pyrodex RS, or 90 grains of Goex 3f or Pyrodex P. Pretty democratic about loads, taking heavier or lighter well too. Just seems to digest what you feed it.
Just so long as the patch/ball combo is pretty tight. I'm using a .535 ball with a .018 ticking patch and a light smear of TOW mink oil tallow for lube. Takes a pretty good whack on the short starter to get it going. But if my patch/ball combo is any looser, accuracy goes south pretty quick.