Why would there be no serial number on a Winchester Model 1886?

All Winchester model 1886 rifles were given a serial number at the factory, stamped on the tang. If there is no serial number on the tang it is likely that the tang was replaced at the factory. This was not unusual. Other common reasons for no serial number: 1. The gun has been aggressively cleaned and the number may have been buffed off. Serial numbers 1 to about 120,000 were lightly stamped. 2. The gun is a stolen firearm where the number was deliberately filed off. These firearms should be shunned by all shooters and collectors.