How old is a mossberg 183 T serial number 713000?

The Mossberg 183 T is a shotgun that was produced between 1960 and 1980. To determine its specific age based on the serial number 713000, you would need to consult a reliable reference or database that provides details on the production years corresponding to serial numbers. However, without that information, it's difficult to provide an exact year of manufacture. Generally, firearms from this series are now around 40 to 60 years old.