You did well at $50. I have two of those though not as nicely finished. I shoot .433 diameter balls with a .015 or .020 patch with 20 grains of pyrodex p. This will give it velocities in the mid 500's for a muzzle energy around 80 ft/lbs. At close range this is a deadly weapon. You can shoot bird shot too as some guys do but I have stuck with balls. Accuracy is marginal, don't expect precise shot placement. At 5 to 7 yards I can hit a paper plate 3 out of 5 times with the other two hitting just outside the plate. It haelps to figure out a consistant hold on the grip. I grip it so the grip screw is just visible over the web between my thumb and fore finger. I have shot at silouette targets at 7 yards and haven't had too much trouble hitting center mass. At close range your going to hit a man size target. Another thing to fuss with on these guns is the nipple. Caps generally don't seat well on them so misfires are common. To fix this I have just filed/sanded the nipple so the caps seat all the way and I can reliably pop caps.
Good Luck,
Don