Watched the Duke in Rio Lobo the other day, amazing how just post-Civil War they are carrying cartridge firearms, specifically 1873 Colts and 92 Winchesters.
As far as good gun handling in movies go, the best I have ever seen was in "Collateral" with Tom Cruise and Jamie Fox. Cruise did a very good job. I watched the making of the movie and the director, Michael Mann, sent him through an intensive combat pistol school so he would actually know how to handle and run the guns in the movie. I think it paid off.