I've done some searching on the subjuct and I have some ideas, for the most part it ain't what most of us are looking for. From what limited information I've found I was hazard a guess that most falls under what I refer to as "reloading" not the same as what most of us do that I refer to as "handloading."
First forget a lot about what you have heard about them killing buffalo several hundred yards away. Some did, to show off but most shot from 200 to maybe 300 yards at most. Remember this was bussiness.
All you have to be able to do is shoot throught the lungs at that distance, the prefered shot, a target maybe what 4 times the size of a deers lung area. 2 moa is plenty for deer at that that range. So to be safe 6 moa is more than plenty.
So just cast some bullets, lube or patch them, deprime and reprime a case, fill it with powder, ad a wad, tap with a dowel and hammer to slightly compress the powder. (I read somewhere at least some did.) and push a bullet into the case. ammo loaded this way is good enough, takes little time and can be done by lantern light.
You need a toot to deprime, if using Sharps cases it needs to be a lever type (Berdan Primers) Winchester or UMC and some of the others you can use a sharpened nail and hammer and do this.
Reprime with dowel and hammer and use same boot heel.
Wads and maybe a cutter.
Most seem to have carried moulds and lead so a pot, dipper and mould is needed. Lube or patch, and seat the bullet on the wad by hand. Crimp with a primative tool if desired, not really needed, carry good factory ammom in your belt in case of emergency, carry the reloads in a bucket.
Back before my cooking took over everything at living history events I did this demonstration for a couple of years at a place I could shoot them. Took lubed bullets, a sharpened nail, a dowel, brass hammer, primers, a can of FFg and a cut off case. Ended up with a load that whooped the muzzle loaders there for accuarcy and splat effect down range the 100 or so yards we shot down into the creek bottom.
When we were done some of the kids would go down and dig out the roundballs in the bank, they could never find one of my 500 gr 45's.
A bit of testing on the range at the farm shows this type load will go 3-4 moa easy at 200 yards. I just had to know.