S1·E9 Bloodline

Luke Saint is a old codger who has a fast draw for a son named Matt. Matt has a reputation, which Luke likes to feed. On the way into Laramie, Matt is ambushed, shot and told he will never shoot again. His pa continues to cause trouble, thinking Matt will avenge him. When he realizes he can't, he goes off and gets Matt's son, Mark, also a crack shot, to get retribution. But Mark is only after Matt.