Wanted, Dead or Alive was a star vehicle in the truest sense of the term. It was a western calculated to exhibit the talent and charisma of its star, Steve McQueen. It lasted for three seasons before McQueen decided to devote full time to the big screen.
McQueen was after some of the most dangerous fellows in the old west, plenty who could shoot a lot better than he. His character Josh Randall needed an equalizer.
In John Wayne's classic western El Dorado, you remember that Duke discovers that James Caan can't hit the broad side of a mountain with a regular six shooter. Before going to El Dorado to aid Robert Mitchum, they stop off and see a gunsmith who fixes Caan up with a Josh Randall special. After that Caan's of considerable help to Wayne and Mitchum.
Of course the sawed off shotgun was also an evil weapon in the wrong hands. Take note of the Dan Duryea western, The Bounty Killer, a very Freudian piece where Duryea becomes hated and feared as a bounty hunter until an innocent bystander gets shot with it.
But with McQueen you knew the weapon was on the side of law and order. As for his Josh Randall character, you can see a bit of him in all the people Steve McQueen brought to the screen like Virgil Hilts, Nevada Smith, all the way to his last two films, Tom Horn and Pappa Thorsen.
Wanted, Dead or Alive was most folks first exposure to a screen legend. I wish that westerns like that were made today.