Posting the information on the cartridge conversion books, got me thinking that we need a Remington conversion thread. Most people do not realize that Remington was converting New Model Armies (1858s) to 5 shot, .46 rimfire revolvers for the US Army in 1868, 3 years before Colt's Richards and Richard Mason .44 conversions.While no one knows exact numbers, the Remington conversions were as popular as the Colts. Just as today, for some models (especially Belt Model .36s), the simple swapping in of a rimfire cylinder gave you a metallic cartridge revolver.
Both books I mentioned have a ton of information on Remington cartridge conversions, including 45 Colt conversions of the NMA (1858). There were lots of Remington conversions that used the two piece cylinder like the R&D. I even read in another book about an 1858 that had a two piece, 6 shot cylinder in .44 henry rimfire. Lots of belt model Remmies had two piece .38 rimfire cylinders...
I actually handled an original .46 rimfire conversion and a .38 rimfire conversion of a belt model with its two pice R&D style cylinder. The Remington conversions (and percussion models, too) were much more sturdy than the Colts, thats why I went with 1858s with R&Ds, instead of 1860s. The R&D cylinders are actually fairly period correct, as Kenny Howell got the basic design from originals.
My CAS persona is an ex-military, now lawman that carries an 1860 Henry and a pair of Remington cartridge conversions in 44 rimfire to go with the Henry. He had a gunsmith in Sonora make the 6 shot two piece rimfire cylinders, and reline the barrel at .440" from .454".