The serial number format often indicates whether the firearm is safe for modern ammunition: First Model (1894–1896) : Identified by a single-post latch ; typically black powder only. Second Model (1897–1908) double-post latch and often has a flat mainspring; black powder only. Third Model / "New Model" (1909–1941) : Features a coil mainspring and was designed for smokeless powder 3. Decode the Serial Prefix (Approximate Years) While specific databases like the NRA Museum Serialization Records
These were redesigned for smokeless powder . The easiest way to tell: The owl logo on the grips faces toward the barrel . On older models, the owl faces the back of the gun. 2. Serial Number Letter Prefixes
Remove the left grip panel to find the primary serial number with its letter prefix. Bottom of the trigger guard: