H. Beam Piper 
Murder in the Gunroom [EPUB ebook] 

Henry Beam Piper (March 23, 1904 – c.  November 6, 1964) was an American science fiction writer. He wrote many short stories and several novels. He is best known for his extensive Terro-Human Future History series of stories and a shorter series of ‚Paratime‘ alternate history tales. 
Piper published his first short story, ‚Time and Time Again‘, in 1947 in Astounding Science Fiction; it was adapted for the radio program Dimension X and first broadcast in 1951, and was re-produced for X Minus One in 1956. He was primarily a short story author until 1961, when he made a productive, if short-lived, foray into novels. He collected guns and wrote one mystery,
Murder in the Gunroom .