The "How to Convert Military Rifles 1966 5th Ed Williams Guide Book" is a nonfiction book published by Williams Gun Sight Co in 1966. It offers detailed instructions on how to convert military rifles, with a focus on the rifles topic in the military genre. The book is illustrated and contains 77 pages, providing valuable information for individuals interested in modifying military rifles. This guide book serves as a valuable resource for those looking to enhance their knowledge of military rifles and their conversion processes.