Check this table for the answer:
http://www.remingtonsociety.com/rsa/questions/barrelcodes
Serial numbers by year for the 870 Remington Model.
what year was serial #1209706V on a model 870 manufactured?
D081337n
Serial 718943w
Look at the date code stamp on the barrel, see related link.
Do a search on barrel codes, I believe that will give you an answer
Check the date code stamped on it. See related link
i do belive it is the last 2 numbers that give you the year
Impossible to answer without a serial number.
100-350 USD
Check this table for the answer: http://www.remingtonsociety.com/rsa/questions/barrelcodes
Go to the Remington Society of America and click the Manufactured link, it has the location and barrel codes for month/year of manufacture.