I've got experience with both the LR and magnum frame NAA cap and ball revolvers, they're fun lil' pistols and quite useful! I load my magnum with 2.0 grains of Alliant Bullseye, the LR frame gets a charge of 1.0 grain of Bullseye. I'm getting close to 1000 FPS with the LR, 1200 from the magnum frame.
Using real BP in these guns is kind of pointless, you're only looking at about 200-300 FPS with the LR frame. Triple Seven really wakes these guns up if you don't feel like using smokeless powder. It's still not as good as smokeless, but they're quite barky with a full load of T7. They can still do some major damage.
Now I use the magnum frame as my go-to gun for when I need something small. It's surprisingly accurate once you get the hang of aiming that little thing. All I can say is practice, practice, and practice some more if you want to get good with your NAA. These guns are accurate, but they take more work to shoot accurately.