Some old info I found a while ago and forever plagiarized:
Remington Year of Manufacture Codes maybe found on the barrel of your Remington rifle [or shotgun] on the left side, just forward of the receiver; the first letter of the Code is the month of manufacture, followed by one or two letters which are the year of manufacture.
According to the "Blue Book of Gun Values", the coding continues as follows:
Month Codes: [first letter]
B - L - A - C - K - P - O - W - D - E - R - X
1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12
Year:______Code: [second (and third*) letters]
1930_______ Y
1931_______ Z
1932_______ A
1933_______ B
1934_______ C
1935_______ D
1936_______ E
1937_______ F
1938_______ G
1939_______ H
1940_______ J
1941_______ K
1942_______ L
1943_______ MMZ
1944_______ NN
1945_______ PP
1946_______ RR
1947_______ SS
1948_______ TT
1949_______ UU
1950_______ WW
1951_______ XX
1952_______ YY
1953_______ ZZ
1954_______ A
1955_______ B
1956_______ C
1957_______ D
1958_______ E
1959_______ F
1960_______ G
1961_______ H
1962_______ J
1963_______ K
1964_______ L
1965_______ M
1966_______ N
1967_______ P
1968_______ R
1969_______ S
1970_______ T
1971_______ U
1972_______ W
1973_______ X
1974_______ Y
1975_______ Z
1976_______ I
1977_______ O
1978_______ Q
1979_______ V
1980_______ A
1981_______ B
1982_______ C
1983_______ D
1984_______ E
1985_______ F
1986_______ G
1987_______ H
1988_______ I
1989_______ J
1990_______ K
1991_______ L
1992_______ M
1993_______ N
1994_______ O
1995_______ P
1996_______ Q
1997_______ R
1998_______ S
1999_______ T
2000_______ U
2001_______ W
2002_______ X