A poster above mentioned the TV western series Yancey Derringer. That series never made it over to the UK, but the star of the show, Jock Mahoney, was, of course, also The Range Rider. I used to love the way he swung on his horse in the opening credits. He also made lots of guest appearances in other westerns. I remember he beating up Gil Favor in an episode of Rawhide, and he appeared as "The fastest fist in the west" in an episode of Wagon Train. He went on to play Tarzan in a couple of early 60s movies.