You can't. You can find the serial number and from that you can get a ballpark figure on date of manufacturer
your Winchester model 12 shotgun was made by Winchester in 1959.
Your winchester model 12 shotgun was made by winchester in 1953.
your Winchester model 12 shotgun was made in 1940.
Your winchester model 1897 shotgun was made by winchester in 1908.
your shotgun was made in 1906
what is the manufacture date of a model 59 winchester 12 gauge shotgun with serial number 262XX
your model 12 Winchester shotgun was made in late 1959.
With the serial number that you provided,your Winchester model 1912 pump action shotgun was made in the year 1941.
1914
year 1939
1939
1961