All Remingtons made from 1921 have a date code stamped on the barrel. The details and table can be found on the Remington Society of America, Manufactures Link.
Check date code on barrel - see related links
go to Remington web site they can help you as they did with my 870 wingmaster
1949 - there is a date code on the barrel for month/year details on the Remington Society of Amerca here: http://remingtonsociety.com/rsa/questions/barrelcodes
Serial numbers by year for the 870 Remington Model.
Production started in 1955 and continues.... The date (month/year) can be determined by the data code stamped on the barrel. A diagram of the date code location and a table explaining it can be found the the Remington Society of America's (collector site) in the manufacture date link. http://www.remingtonsociety.com
1946, it will be date code (month/year - letters) on the left side of the barrel. You can look this up under the manufactured date on the Remington Society of America site.
1909
Manufactured: 1947, value dependent on condition. I bought a model 121 fieldmaster brand new in 1954 and they were supposed to be the first hammerless pump . I do not know what year they originated but , now you know it was at least in 1954 or before . Wish I could pinpoint it better for you but you now have a jumping in point.
The last year of production for the Remington model nylon model 66 was 1990.These rifles were made from 1959-1990 with a total production of 1,050,336.
1919
It was in production from 1931 to 1949, when it was superseded by the Remington 870.
Depends on the model.