Factual error: The Apache spearhead Buck appropriates is very obviously made from machine-tooled steel. Indian tribes in 1870s Arizona made their weapons points from hand-knapped stone and on rare occasions, iron. They never developed steel-making technology.
The High Chaparral (1967)
1 factual error in Auld Lang Syne - chronological order
Starring: Cameron Mitchell, Leif Erickson, Linda Cristal, Henry Darrow
Genres: Western
Gold Is Where You Leave It - S1-E19
Revealing mistake: Buck lights the fuse and tosses the dynamite-filled barrel at the bad guys. We see the explosion. Unfortunately, after that, we can also see the intact barrel still rolling away in the dirt.
Billy Blue Cannon: I need all the rest I can get, Uncle Buck.
Buck Cannon: When I was your age, Blue, the word 'rest' hadn't been invented.
Trivia: While shooting an early episode, Mark Slade fell from his horse and suffered a painful bruise when he landed very hard on the gun at his hip. After much pleading, he convinced the producers and the prop dept. to make a replica pistol out of rubber. Replaced by the real one only when it actually had to be fired, the fake gun remained in Blue Boy's holster for the rest of the show's run.