The late William Goforth, a leading authority on Iver Johnson firearms, compiled a seminal book often cited by gun forums. His research is considered the "best" authority. While the book is out of print, many collectors cite his data, which is available in research threads on forums like The Firearms Forum. 3. Quick Reference Tables (Prefix System)
Specialized groups on platforms like Reddit provide peer-reviewed identification based on visual markings. Iver Johnson Revolver Serial Number Database BEST
These are the most common "top-break" revolvers. Identifying the is the first step to narrowing down the date. Production Years Key Identifying Features First Model 1894 – 1895 Single post latch system. Second Model 1896 – 1908 Double post latch; flat leaf springs. Third Model 1909 – 1941 Double post coil springs ; rated for smokeless powder. Common Serial Number Prefix Codes The late William Goforth, a leading authority on
3rd Model (1909–1941). These were redesigned for smokeless powder . 2. The Letter Prefix Identifying the is the first step to narrowing down the date