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He does have a brace of NMA's. He took them from the body of a young Union officer following the Battle of Wilson's Creek in Missouri. One of them usually stays in his gear (in his saddle bags, on a pack horse, or in a wagon).

The 1866 Winchester came from an aggressive but unwise Comanche in the ...

Okay, I've done a fair amount of looking and measuring and thinking and...

Since the bore on the Remington NMA is the same as the diameter of the .45 Colt bullet, I'm going with .45 Colt. It was introduced in 1873 while the "conversion" would have happened in 1875 or so. My character will pull a ...

As long as it's for a novel I don't think it really matters. A good smith could chamber and time a NMA for any of the rounds mentioned. Also, have you ruled out rimfire rounds available during this time period?
It really matters, considering the likely readership.

I have considered the rimfire ...

In another thread on another topic, someone suggested the . 44 Smith & Wesson American cartridge, aka .44 American, might be a worthwhile round to consider. It was introduced in 1869, so it would be 'established' in my timeline. The bullet diameter is a little small, but the bullet was heeled.

So ...

Yup, the .44 Colt came out in 1871. Thanks!

Glad to have found this site! I was active in Cowboy Action Shooting (SASS, Western 3 Gun), and put maybe two thousand rounds of .45 Colt thru my pair of Uberti '58 Remmies using R&D conversion cylinders. I am in early development for a novel that takes place in northeastern New Mexico, circa early ...

I'm a writer, in the early stages of crafting a novel that takes place in northeastern New Mexico in the early- to mid-1870's. Here is my question:

Would it have been feasible for a skilled gunsmith of the era to convert an 1858 Remington New Model Army revolver to .44 Colt (not .45 Colt -- it came ...