In past centuries, gentlemen carried flintlock solitary-shot pocket pistols, in some cases even with just a little folding bayonet on them, within their tailcoat pockets. That gave strategy to the percussion solitary-shot that even nowadays even now bears a Edition of Henry Deringer of Philadelphia’s name. William Elliott’s Double Derringer, https://elliottmvusp.bloggazza.com/32213477/everything-about-olding-pocket-pistol