The Quiet Gun by Lauran Paine

Lauran Bosworth Paine (born February 25, 1916 in Duluth, Minnesota-died 2003 in California) was an American writer of Western fiction. Paine wrote over 900 books, including hundreds of Westerns as well as romance, science fiction, and mystery novels. He also wrote a number of non-fiction books on the Old West, military history, witchcraft, and other subjects. Because his publishers only accepted a limited number of books under a single author's name, Paine adopted dozens of pseudonyms. Many of his books, published by Robert Hale of London and distributed solely in the UK, have only in recent years been appearing in the United States, usually as large-print editions.