Gunsmoke - Season 17 Episode 12 : Gold Train: The Bullet (1) 1975

A hidecutter starts trouble in the Long Branch and Matt comes to the rescue throwing him out of town. When Festus goes up to fetch Dr. Chapman, he finds the old scudder there himself. Offering to buy Doc a drink, he can't resist and they surprise everyone down at the Long Branch. While they are all excited to see Doc, Matt is out checking the town and ends up shot in the back by the hidecutter he just threw out. Doc's homecoming is ruined when he realizes that if he tries to remove the bullet he could paralyze Matt and he doesn't want to be the one to do it. So, he contacts a surgeon in Denver, and loading Matt in the baggage car of the train, Kitty, Doc, Festus, and Newly all head for Denver along with a Federal gold shipment.