This one isn't from a "cowboy" western, but it's close.
"I, Hatchet Jack, being of sound mind and broke legs, do leaveth my rifle to the next thing who finds it, Lord hope he be a white man. It is a good rifle, and killeth the bear that killeth me. Anyway, I am dead. Sincerley, Hatchet Jack."
Need the actor who spoke those lines, his character, and the movie.