Your Browning superposed,over under 20 gauge shotgun was made in the year 1951;with the serial number that you have provided.
Not a valid Browning serial number.
1924
1980
You will have to provide the serial number. Alternatively, you can call Browning with the serial number and they will tell you. Some serial number information is on line at their website.
Provided that is the entire serial number, 1912.
1929
Impossible to answer without the serial number.
You will have to call Browning.
This gun was made in 1950.
1950
1931
You must provide the serial number for the question to be answered.