Howdy
I have two 1858 Remingtons set up for 45 Colt.
This one is my old EuroArms remmie that I bought back in 1975.
I also have a Stainless Uberti that I bought used and the conversion cylinder was included.
Now, before anybody poo-poos putting a cartridge cylinder in a C&B revolver, let me explain something.
Why would you pay $240 for a cylinder when you can buy Uberti's 1858 cartridge conversion revolver already set up for cartridges for $578 msrp, probably less on the street? I bought my old Remmie so long ago that paying around $180 for the cylinder a bunch of years ago was like buying a new revolver for $180. I have no idea what I paid for it in 1975, but it could not have been very much. So over the years, its cost has been amortized, and buying a cartridge cylinder for it was like getting a new shooter for $180.
All that said, if you buy the right brand of cylinder you can make it a C&B revolver again by just putting the C&B cylinder back in. If I wanted to (which I don't) I could pop the original C&B cylinder back into my old Remmie and ti would be a C&B shooter again. There was no change required to the revolver itself for it to accept the cartridge cylinder.
There are currently three different makers of cartridge conversion cylinders for the 1858 that I know of. There is the original R&D style cylinder that is sold exclusively by Taylors, there is the Kirst version, and there is Ken Howell's Old West Conversion cylinders.
I have the old R&D type cylinder for my old Remmie. It appears Tidewater Kid has the same one.
This is the only 45 Colt conversion cylinder you can buy for the 1858 Remington that has six chambers. The others only have five. The reason for this is that you cannot fit six 45 Colt sized rims into a cylinder for the 1858 Remington without the rims interfering with each other. The cylinder is not big enough to do that without the rims interfering with each other. So Ken Howell, of the original R&D company came up with the concept of angling the chambers out ever so slightly, less than 1/2 of 1 degree, so six cartridges could be chambered without the rims interfering with each other.
When I first bought this cylinder, it could not accept the wider rims of the 45 Schofield cartridge (.520 vs .512 for 45 Colt. However I had a gunsmith open up the counterbores slightly where the rims sit so the wider rims of the Schofield round could be seated too.
I'm pretty sure that all this style cylinders are coming this way now, so they can accept the Schofield rounds as well as the Colt rounds.
So why do the others only have five chambers in this caliber? Again, the diameter of the cylinder, and the distance from the center of the cylinder pin to the center of the bore dictate it. The weird thing is, Ken Howell patented his idea for the angled chambers. Then for some reason he sold the patent to Taylors. When he started up his own company, the Howell Conversions company, he was prevented by his old patent from angling the chambers to fit six chambers in the 45 Colt cylinder. If you go to Howell's website, you will see he sells a six chamber cylinder for the 1858 Remington chambered for 44 Colt, not 45 Colt. Don't make the mistake of buying that one. You will need to be firing 44 Colt ammo, with its heeled bullets. Not the same diameter as 45 Colt.
Kirsts's conversions a utilize a plate you screw into the frame to back up the cylinder, very similar to the original 1858 Cartridge conversions.
Like this:
The R&D (Taylor's) and Howell cylinder use a separate plate with multiple firing pins as in my photos. The beauty of this arrangement is that the cylinder is so easy to pop out of a Remington. Unlike the Colt C&B revolvers, you don't have to pull off the cylinder and you don't have to cut a loading gate or loading trough in the frame. You just pop out the cylinder, poke out the empties, fill the cylinder back up, and pop it back into the revolver, ready to go.
I only shoot Black Powder in my cartridge converted Remmies, Generally the Schofield rounds instead of the more powerful Colt rounds. I will tell you that because the original 1858 design lacked a bushing on the front of the cylinder, they tend to bind up faster with Black Powder than more modern guns with a Bushing on the front of the cylinder. But if you already shoot C&B Remmies you probably already know that.
One other thing. Guys often question the idea of angled chambers and how it will affect accuracy. I can positively state that my Remmies with their R&D conversion cylinders are the most accurate 45 Colt revolvers I own. More accurate than my Colts, Ubertis, or Rugers. This is because the chamber dimensions for the cylinder are very exacting. More so than the chamber dimensions of any of the other brands. As a matter of fact, when loading 45 Colt I keep one of my R&D cylinders on the bench and use it as a cartridge gauge. I know that any round that will drop into the tight chambers of the R&D cylinder will also drop into the sloppier chambers of the Colts, Ubertis, or Rugers.