Hello John,

Winchester introduced the Model 1200 in 1964, with serial numbers beginning at 100,000. In the year 1968, a “G”  “L” prefix was added to the serial number (to be in compliance with the Gun Control Act (GCA) of 1968). Your Model 1200 was most likely manufactured sometime in the year 1966.

Bert

Tom D said
Bert, I think you meant to say an L prefix was added to the serial number in 1968, not a G prefix.  

You are correct.  I had just finished discussing a post-63 Model 70 with someone else, and it had the “G” prefix.

Bert

Jeremy said
SN 367119 around the same time of 1966?  

It is definitely Pre November 1968, as it does not have the “L” prefix. 

Bert