Between the years 1942-1945.
It would be better to ask Remington that question.
Remington made one can the Remington 17 about 30 years ago.
1984 thru 1987
1959 to 1989
Since 1967
http://www.remingtonsociety.com/rsa/questions/barrelcodes
Your Remington 1903-A3 was made by Remington in 1942.
No. Remington shotguns are made in the USA.
Made in 1918. 100 years old this year.
1982-1987
The Model 1100 has been in continuous production since 1963.
They were made from 1936-1941, few after 1939. Value depends on condition.