(SAA/Peacemaker) was first made in 1873. Before that revolvers were black powder percussion revolvers, such as the Colt Navy (.36 caliber), the Colt Army (.44 caliber) the Remington, Starr, and many more made in the US. I want you to please take time to study this and get it right - there is NOTHING that makes me lose interest in a book or movie where guns are a big part of the narative when it is obvious that the writers don't know what they are talking about. I suggest you go to a large gun shop - Cabela's comes to mind - and check some of the single action revolvers used in Cowboy Action Shooting today. Even buy a modern repro black powder revolver (Get a Colt Army) and get familiar with it. (Under $300). They are a lot of fun and very intersting to shoot.
I will send you to this auction site so you can get some idea about what was what:
http://www.armchairgunshow.com/Any books by Jim Supica or single action revolver shooting books by Mike Venturino would be very valuable - Mike is more practical shooting stuff.
Google "Single Action Shooting Society", "Cowboy Action Shooting", Old West guns, 19th Century firerarms, etc and follow where they take you.
Be warned of 2 things - you can make a career out of finding out about these guns and they are very addictive to shoot and own, and god help you if you have a lot of money - they can get very expensive.
Enjoy your education and good luck.
FWIW, I have been doing "field research" on various guns for over 50 years and I'm no expert.
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