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.
While shooting an early episode, Henry Darrow 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 Manolito's holster for the rest of the show's run.