hoo boy am I not interested in differentiating between types of guns. :shrug-outta-hecks: I’ve never been particularly interested in them, so when the stats are similar I don’t know what to differentiate them by. Just resorting to looking several up to get a feel for how I want to equip NPCs or pregen PCs and finding this to be the most irritating part of the research I’ve done for the setup. What research have you had to do for games that you found particularly tedious?
You already got single or double action accounted for so the other two main functional differences are what size bullets they use and if it uses black powder like a musket or cartridge bullets like a modern gun does. I’m not a rpg expert but mechanically I’d use caliber as different damage die/bonus and reload mechanism as making it take multiple turns/impossible for black powder guns to reload mid fight. For an example of a cartridge loading gun the colt single action army is pretty iconic, and the colt navy is a good black powder one.