I'm not a huge Fred MacMurray fan when it comes to Westerns, I guess, but he could do a credible enough job as he did in At Gunpoint. The basic storyline involves a store clerk who shoots one of an escaping band of robbers. Only by a lucky shot does the clerk actually hit and kill one of the robbers; the dead guy's brother who is also in the gang makes it his personal business to get revenge, especially when the newspapers glorify the action of the clerk in shooting down the bad guy.
This movie has one of my all-time favorite Western character actors, Skip Homeier, who is the bad guy seeking revenge. (Homeier and MacMurray are also a protagonist / antagonist pair in another Western, "Day of the Bad Man", where MacMurray plays a judge.) In this movie, MacMurray's son is played by Tommy Rettig of the 'Jeff's Collie' (i.e. 'Lassie') TV show and he is rather annoying in the role. Maybe the director wasn't paying as much attention to him, as Rettig was really very good in 'River of No Return' with Robert Mitchum. (The lucky kid had Marilyn Monroe's hands all over him during that movie!) Walter Brennan, another great, is in this movie and as a testy old doctor, he has some pretty funny acidic observations to make. When his best friend and checkers-partner gets shot and killed, Brennan underplays the scene where he sees that his friend is dead - and he does so masterfully. He gives only the slightest view of his anguish but you can tell he's devastated. Brennan was a giant of the Westerns and he's great in this movie as always.
I think the premise of a story is all important and this movie has a great one - take an ordinary guy, give him beginner's luck at accidentally beating the bad guy, then have the rest of the bad guys come back seeking revenge. Don't compare this movie to High Noon as one other person did, because it's really not the same theme. Frankly if I had a choice of which one to watch right now it would be this movie, At Gunpoint. (And I do like High Noon very much, but this is also a darned good film.) You won't waste your time by watching this one. If you like Westerns, this is one you will enjoy.