There was serious interest in the Old West lawmen and gunfighters up through WWII. Some writers went into some detail about some of them and I believe Rex Applegate even visited their graves. Of course that was before the new wave of gunfighters and shooting school master. So they tried to learn as much as they could about how the old-timers did it (when they were young) since it appeared they knew what they were doing.
The so-called adult westerns of the 1950s and early 1960s helped to maintain that interest, although that interest took on a different form with various kinds of handgun competitions. That's where Jeff Cooper came in, you know. Other writers also made frequent reference to the fast draw hip shooting arts and some of them had killed men, so they were serious about what they were writing about, not just games with guns. They tended not to make references to the movies, however.
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.