what is your rifle brand?
BP long-guns: (must also say, I've taken many, many deer with all these guns).
#1) Bought a used 'brown barrel" CVA Hawken when I was 20 for $75. I'm now 53. Used that for YEARS until the in-lines came out. Likes 70gr Swiss 2f and round balls. Still have it.
#2) Bought a used, stainless, T/C Black Diamond for $125 used it for many more years. Put a Tasco 3-9 $120 scope on it. Likes 120gr T7 pellets. 250gr sabot's - Shockwaves, Hornady's (same thing), and Barnes TMZ's and MZ's. Still have it.
#3) Got a new T/C Encore. Camo stock, stainless, Top of the line at the time. Shot very well right out of the box. First one to have the 209 ejector swing to the side without taking the gun apart to remove the breech plug. Put a 3-9 Leupold scope on it. Likes all the same sabot/powder as mentioned in #2. Still have it.
#4) Bought a new T/C Triumph. Camo stock, "Weather-Shield" barrel, 1st one to have the breach plug removable without any tools. Put a Nikon "Omega" 3-9 scope on it. This one gave me fits in the beginning. No matter what I did, I couldn't group well. Finally after shooting about 30 rounds through it, somehow it finally broke in. THEN it almost didn't matter what I put through it, it shot exceptionally well! LOVE the Omega "Drop compensating scope". Likes the same sabot/powder as in # 2 and #3. Still have it.
#5) My son was graduating college and I ordered 2 CVA Accura's, 1 for him and of COURSE I had to have one too.
Camo "thumb-hole" stock, stainless, same Omega scope as #4 on both. By this time, CVA also had the removable breech plug requiring no tools. Likes 245gr PowerBelts and again 120gr of T7 pellets. Interesting difference, mine also likes the Barnes sabots mentioned above, but my sons gun hates them. Go figure. Still have it.
Conclusion: I MIGHT get a slight accuracy advantage in using loose powder rather than pellets. Not worthy of extra hassle in the field. With real BP, compaction is a BIG factor, while T7 (loose powder) they recommend little to almost no compaction. Had no cleaning or accuracy advantage using White Hots over T7 pellets. If I can't get a 2 inch group at 100yds. I'm not happy. I swab my barrel's with pre-soaked and dry patches between every shot even in the field. I want every shot to be the same as the one before. (not to mention getting the sabot plastic fouling out of the barrel while it's still warm)! I have had Shockwaves and Hornady's (that were NOT "bonded") (they do also sell bonded sabots) fragment in the meat. Also had the happen with PowerBelts. Never had it happen with the Barnes. I would take any of these guns in the field as I know exactly what they like and what they will do.
Didn't intend on writing a book about this, but got carried away and hope I covered enough to answer your question! (LOVE talkin'-bout BP)