I cast all my own bullets and so far I have 5 different moulds ranging from 385 to 570 gn. You will need to slug your barrel and see what size of bullet you need, my 1874 is .459 so I have to load a bullet at least .460 or .461. You will have fun with it and definitely get looks at the range especially when the young guys with their 6.5's with huge scopes ring the 500 meter gong and you are right beside them doing the same thing. It is fun to watch the 20 somethings all hi-fiving themselves and feeling like they are the next world class sniper and I roll out the old smoke wagon and flip up the tang sight and lobe one across the range and "ding". Gets quiet real quick. I had a couple of them getting kind of huffy , good times.
Since the Holy Black is non-existent or nearly so right now I have concentrated on smokeless powder and honestly the group sizes are not that much different than black powder. Most of the heaver bullets (500+) will keep inside 2" at 100 meters and my go to bullet which is the 535 postell with Varget will print 10 shots inside 2.5", which is basically a hole.
My wife bought it for me for my 50th birthday, she and my brother sourced it in Montana and when we were taking a trip down thru there she told me about it and we needed to pick it up before returning home the next week. Kept it quiet from me for over 18 months, couldn't figure out why she was all powerfully existed to go to Custer's Last Stand in Wyoming .