Little is known today about Beyer. He worked his way through the Drexel Institute (now Drexel University) in Philadelphia, Pennsylvania, by selling radio receivers. He subsequently worked at many other jobs including taxi driving, sales, railroading, and police work. At one time he was captain of the Philadelphia police radio and communications department.
Beyer also signed his work William Beyer, Bill Beyer, and Wm. Gray Beyer. At least one reference source lists him as William Grey Beyer, but this spelling of Gray is undoubtedly a misprint.
Novel-length stories published in Argosy Magazine include Minions of the Moon (1939), Minions of Mars (1940), Minions of Mercury (1940), Minions of the Shadow (1941), Death of a Puppeteer (1946), Murder by Arrangement (1948) [aka Eenie, Meenie, Minie – Murder!], and The Deadly Thinkers (1951).
Beyer is almost completely forgotten today, with only his Minions of the Moon ever mentioned in the genre literature. At one time, however, his stories were very popular, especially the ones that ran as serials in Argosy. These SF novels were fast-paced and had a certain appeal.
For more on his career, see http://www.sf-encyclopedia.com/entry/beyer_william_gray