As for reloading, I use Starline 32-20 brass, Meister Hard Cast 100gr DEWC
and Lee's dies with VihtaVuori N105 powder. A nice mild load of 7.2 grains of N105 with a COAL of 1.375" gives me ~800fps ... QuickLoad predicts that performance will happen with N105 at about 11,000 PSI.
Be safe and work those loads up yourself ... this isn't supposed to be a barn burner, so go easy! I'm sure that KraigWY will chime in with his recipes as well ... I'll be looking to see what I can learn from him. Beware that some batches of brass need to have the cases trimmed for them to clear the thin gap in the Nagant pistol ... IIRC, mine worked without trimming ... but I just checked my database and it was 2005 when I got and prepared that brass, so I could have forgotten something by now.