Most of my sources say the Model 1 was a seven shot .22. Looks like there was a six shot .32 caliber revolver Smith and Wesson (and a smaller five shot version) produced later as well.
Lack of stopping power seems to be why the Model 1 was never as popular as the Colts. Smith and Wesson did make larger caliber revolvers later, such as the .45 Schofield. That was the gun the Jesse James and John Wesley Hardin have been said to have carried.

Another reason may have been once a rimfire cartridge was used, it could not be reloaded. The cartridge is deformed when fired.

Also, since loading a cap and ball revolver was so time consuming, it's said the some users would carry extra pre-loaded cylinders and swap those out to reload.
There were also variations of paper cartridges. The user inserted a nitrated paper wrapped portion of powder and shot. It still required the separate percussion cap of course.

Yeah, it can be pretty confusing, especially when you consider there were variant and customized models on a lot of the firearms from that time (different barrel lengths, calibers and so on.) For example, there were Colt "Peacemakers" in .45, .22, .38, .44 and so on.  There was even a variant of the Sharps carbine with a coffee mill in the stock.



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