Period correct '74 Sharps Buffalo Rifles?

[Don McDowell]

The Hartford collar was a result of the way Sharps manufactured the barrels, it has no specific purpose after that.
On the 40-90 you can get headstamped brass from Bertram and Rocky Mountain Cartridge and if you go that route I have some of those you could get ahold of. Fouling in the 40-90 isn't any worse than any other big bore cartridge, or at least it hasn't been with a proper charge of either Cartridge or Olde Eynsford 1f. If I were going to use it as a hunting gun, I would get one of the dual diameter sharps moulds from Brooks, .400 or 401 on the base with a 395 nose , with the original postel nose shape.
On the 44's if you could scare up some of the Jamison/Captec brass, load it with OE 1 1/2 and shoot the dual diameter bullet I have from Brooks.
With the 45's I also have a dual diameter bullet that will allow for shooting dirty.