All four of Chuck Connors' sons appeared in one Rifleman episode
Filming the episode took twice as long because the kids kept ruining takes!
In The Rifleman episode "The Schoolmaster," Arnold Moss plays a strict, no-nonsense teacher new to North Fork. The story starts when Lucas brings a group of children to school on his wagon. As they arrive, Schoolmaster Griswald chastises Lucas for bringing the children 12 minutes late.
Mark and the rest of the kids in the class soon learn what they're in for when Mr. Griswald informs them that "the standards at this school will be as high as they are at the Boston Academy." The new rules don't come easy for the kids, especially Mark's impulsive friend, Billy.
After Mark gets blamed for one of Billy's pranks, the pair decide to skip school and explore an abandoned mine. They're not there long when a collapse traps Mark inside. In the end, Lucas and Mr. Griswald have to put their differences aside to save the young McCain.
The episode is dramatic and tense onscreen — but behind the scenes was a friendly family affair. Chuck Connors brought his four sons to work with him to play some of Mark's classmates. Even more desks were filled by Connors' two nieces and the children of the show's producers Arnold Laven and Arthur Gardner.
According to a piece in LIFE Magazine from the time, having so many kids on set was fun but also time-consuming. The article reveals that filming the episode "took double the usual time as the children waved at the cameras, missed cues and laughed at the wrong time."
It also gives a hilarious tidbit about the end of the shoot. "The scenes were finally done to everyone's satisfaction — except a four-year-old who asked after a ninth retake, 'When does the show begin?'"