Remington Speedmaster 552

How do you tell the difference between the 552A and the 552 BDL?

Is there a website to look up Remington serial numbers?

The sights on the BDL are more substantial: ramped front vs. little dovetailed post with bead, and fully adjustable rear vs. stamped with step elevator. Also, the BDL has a checkered stock.

For a born on date, Remington puts a code on the barrel.

Shamelessly stolen from Rimfire Central:

Remington Year of Manufacture Codes may be 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. For shotguns with removeable barrels, the code will be valid for the manufacture of the barrel; maybe for the receiver, as barrels do get switched around.

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

* the years 1943 though 1953 had double letters: ie, MM = 1943

As may be seen, the year code letters duplicate; some knowledge of when the model was introduced should resolve the actual year of manufacture.

Simple way.
552A has uncheckered, oil finished, walnut stocks.
552BDL has varnished, checkered walnut stocks with a slight Monte Carlo comb.