I carry an "American derringer many times if I just want a gun I can slip in my pocket, it is also a .45 Colt/.410. It is well made and machined not cast and could handle hot ammo. However since this is a close range gun, a few feet, I carry .45 Colt cowboy ammo in it. The projectile has enough speed and weight to stop a man. You don't have to shoot the real hot stuff like I carry in my revolver.
When you are up to your butt in alligators, it is hard to remember your intent was to drain the swamp. Stay focused!