Date code stamped on left side of barrel, go to Remington Society of America for diagram and chart.
By the serial number and markings on the barrel.
The exact value of a Remington Sportsman 12 Magnum actually depends on a couple things. Some of these things would be the condition and age of the Magnum.
The value of a 20 gauge Remington Sportsman 58 would actually depend on a number of things. A couple of those things would be the age and condition.
Let me know if you find out , I have the same gun with s/n 14291 bob.azbell@yahoo.com
Can't be answered without a serial number.
Impossible to answer without the serial number.
You can look on remington's website, but judging by the serial number it should have been made in 1980.
1914
Serial number and features
What is Age of Winchester 1897 D 16 gage serial number 413803
1920
Manufactured 1927