Obscure
Well I adore my little Martini in 380 Long.
Cases are made from 38 Long Colt, .375-80 heeled bullets can be bought or made, 3.5grs of Trailboss somehow is my lucky ticket but the same of Titegroup or 4grs of Unique work too.
But, I don't think you'll be shooting that one 200yds. It's very quiet, and accurate. I've really only shot to 50yds for my walking area of forest.