Congratulations on the ROA. They really are a lovely gun to use. 12 grns is a very light load even using Swiss but
until you start experimenting with loads you won't know what your particular revolver likes. Both of mine seem to
shoot well with 20grns of TS2 with two level .7cc scoops of semolina to fill the gap between powder and ball. Whatever
loads you use be aware that black powder needs to be compressed slightly so make sure you use enough filler/wads
to fill the gap. Don't worry about exact amounts but make sure theres no air gap. Obviously the more powder used
the less filler/wads needed. Aim to have the ball just below the cylinder lip.
If at first you can't hit the target board let alone the black don't give up, it takes time and practice to get good with
any revolver. Start out with two hands if you need to but keep your fingers away from the cylinder, powder burns
aint nice.
Above all enjoy your Ruger and if in doubt ask. Let us know how you get on. Tim