How old is western field 22 14m 390b?

The Western Field 22 14M 390B is a model of rifle that was produced by the Mossberg company in the mid-20th century, primarily during the 1960s and 1970s. As such, its age can vary based on the specific year it was manufactured, but it is generally considered to be over 50 years old. For precise dating, one would need to check the serial number or any specific markings on the firearm.