That's my two main guns ,I have a 50 and a 45. I load 115 grains of Blackhorn and a win 209. I modified my BP by drilling it through with a #21 drill and tapping with a 10x32 tap and put a Lehigh vent liner in it. I clean from the vent liner to the 209 seat with a #21 drill every 10 or 12 shots to keep the carbon down this is a common need when using Blackhorn but you do not clean between shots. I have fired 30 or more shots with out cleaning but always clean when done shooting.
The other load I use in the 50 is my long range load I use a 250 grain or a 200 grain Shock Wave with a Harvester sabot [short black for the 250 , for both 250 grain bullets].