With Jamison/Captech defunct, the only source of empty .44-77 brass, outside of turned-from-solid cases, is reworked cases, from those with a .50 caliber Winchester base and rim. The cheapest and easiest to find in this group is the .348 Winchester, with a length of 2.50", a base diameter of 0.547" and a rim diameter slightly larger than 0.600".
The reformed cases will fit the chambers of Shiloh Sharps and (presumably) other modern replicas. Whether they fit original guns must be determined by their owners. The price of reformed cases is reportedly $3 each. Therefore, it is worthwhile for an owner of one of these rifles to know how to make a few shells, in self-defense, if for no other reason.
I got some .44-77 shells along with my rifle, made from .348 Winchester. These have base diameters of 0.518"-0.520". Swaging the 0.547" bases of the .348s is a major reduction, requiring specialty forming dies and an industrial size press. The base is hard, to withstand the primer detonation, firing pressure, and back thrust. Further reduction might cause it to crack. Annealing it for this operation would allow the primer pocket to be distorted in forming, and the first primer fired would likely enlarge the pocket and allow gas blowback, rendering the case useless for further reloading.
So the only recourse for the home mechanic is turning off a portion of the base, from 0.547" down to the .44-77 base diameter. I used 0.519" as a target diameter. I made a tightly fitting mandrel for the .348 case neck, centered it in the lathe, pressed a case on the mandrel with the live tailstock center, and turned the base down. I picked a length for the turned-down section of 0.195" ahead of the rim, running the longitudinal feed in reverse. I could take it down 0.005" or so at a pass and the friction of the setup would allow the case to spin against the tool bit.
I took the turned cases and slowly squeezed them into my .44-77 sizing die. The 0.195" turned section was best for allowing the swaged down brass in the case body to blend in seamlessly with the base. Shorter turning lengths resulted in an ugly ring of brass hanging over the turned down area, and the case would size no further until this ring was removed. A longer turned section makes a ring in the case body, which may or may not cause a stress riser on firing, so I preferred to avoid more length.
This sizing operation is not without its hazards; I wound up cracking the sizing die after less than 20 cases. I have a new one on order; but it was an expensive lesson, the equivalent of buying about 50 formed cases. But, as my old Chief Chemist used to say, "Experience is gained in direct proportion to the amount of equipment ruined." I'll make a heavy tool-steel ring die to bring the diameter down on the next ones I do, and use my Harbor Freight hydraulic press instead of the RCBS 2A. The RCBS was up to the job, if the die was screwed in gradually, but it did add to the time and effort required. Imperial Sizing Wax was used in this step.
After the turned and formed shells were checked for chambering, they were loaded with 11 gr Unique, the case filled with Cream of Wheat and a blob of wax, and fired. They blew out to fit the chamber, although they were a little short (2.40"+ from 2.50"), and I havent checked the neck thickness yet. About half he original formed cases that came with the rifle had been neck-turned, and fit grease-groove boolits well, but I prefer the unturned cases, since the thick necks hold bore-diameter paper patch boolits better.
Anyway, the process is proven out, to my satisfaction at least. A little more tooling, and the rifle will shoot as long as .348's are out there.
From left to right, .348 Winchester shell, shell turned at base and swaged to fit rifle chamber, fireformed shell, sectioned shell to show brass thickness, and an example of the need to anneal the necks a little softer than I usually do in the paper-patch loading process. Also shows the "step" that results from turning a longer section on the base.
The brass at the base is still a few thousandths thicker than it is further up the case body, by my Starrett tube micrometer. I haven't fired any with full loads yet, but it should hold the pressure of blackpowder loads. The ones that came with the rifle do, anyway.