Never a black powder gun but I've dropped one or two revolvers when practicing drawing, which I don't especially like to admit. However, the worst case was when the Browning Hi-Power fell off a shelf about eight feet off the ground and landed on the hammer on a concrete floor. But nothing broke or bent.
That's what I call the jelly side down theory of dropped objects.
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.