Sarge,
Welcome to the forum, and thanks for your service.
I'm a bit confused - you bought a bp revolver and you want to shoot smokeless in it - do I have that right?
BP revolvers are intended to shoot black powder or black powder substitutes ONLY. NO, repeat, NO, NADA, NONE, ZILCH, ZERO smokeless powder at any time for any reason in any amount.
You may use real black powder (Goex, Swiss, KIK, etc.) or one of the substitutes (Pyrodex, 777, American Pioneer, Goex Pinnacle, etc.).
These powders come in granulations of ffg and fffg (there are also fg, ffffg and 7f, but forget about those for now), or in the case of Pyrodex, RS and P. You should select fffg or Pyrodex P for your pistol.
Also, limit your powder loads to 25 gr by volume or less, as heavier loads will, over time, damage the frame.