Year of Manufacture is stamped behind the serial # on the left side of the receiver.
Date code is stamped on barrel, see related links for information on the Remington Society of America.
Remington Society of America site: barrel code stamped. http://remingtonsociety.com/rsa/questions/barrelcodes
its the manufacture.
Your question cannot be answered without you providing the name of the maker of your shotgun,and then we can determine if there is any public data to identify the year of manufacture.
If the case is not stamped with the manufacture, there's a good chance your not going to know for sure. Major manufactures stamped their leather, if where the stamp was is missing it MIGHT be identified by sight.
Date code is stamped on the barrel, left side in front of receiver. Check Remington Society of America for the codes.
its the manufacture.
The date stamped on the collar is the manufacture date NOT the expiration date which I see a lot of people writing. I am a propane retailer, just got a load of new tanks all stamp 09/12. They are good for 12 years from the manufacture date.
100 USD or so.
Those are modern day reproductions of an antique firearm. There is generally a letter stamped in a hollow square that can be used to determine the manufacture date- and you can always ask the manufacturer- info@zoliusa.com
If you take it apart, it is possible that there may be manufacturer marks, but the number stamped is no indication of the manufacture. If it has any unique features, such as the early lever operated ball return, it can help to identify it.