While talking to the Marshal, Lucas confirms his rifle is a 44-40 caliber.
I've always thought that The Bullet was serving as a pilot for a new TV show starring Harold J. Stone as a forward thinking Marshal / ballistics expert that was never picked up.
Final of 6 appearances of Richard Anderson. Anderson appeared as different characters on a more or less annual basis- once in 1959, twice in 1960, once in 1961, once in 1962, and finally here in 1963. As was the case here, he was nearly always a heavy or bad guy.
Although everyone else called him marshal and Lucas knew the lawman in a New Mexico town (such as Micah) was the marshal, Lucas calls the marshal sheriff when he leaves the office. He did this on purpose since the marshal had called him the wrong name (Cain) twice.
Final of three appearances of Harold J. Stone. His first and last appearances were very near the beginning and end of the series. In this final appearance, he was at first portrayed as a bad guy that was really a good guy. Similarly, in his initial appearance in Season 1 in Home Ranch (1958) he was at first the bad guy that had a change of heart and turned good.