While his character briefly escaped the hangman, in real life the actor playing him, Don Kelly would not be as fortunate. Kelly would pass away in 1966 at age 42. He would be the first of the main credited cast to die, as even Harry Cheshire (Judge Traeger) outlived him, passing away in 1968. As of 2019, only Robert Fuller remains alive. Ironically, his character was the first to die here.
The title refers to the bullet removed from Davey. Doc tells Dan it's a souvenir, and Dan uses the same term at the end when he gives the bullet to Johnny.