Any BSS is rare as only about 1,200 or so were made. Made from 71-87. Gold triggers started in 1978
If you have the money....
1972
With the exception of 10-25, all BSS had a single trigger
1986
12 gauge BSS were first made in 1971 and 20 gauge in 1972.
You must call Browning with the serial number to find out.
1976
The BSS
1972
50-1000 usd
Made before 1975
1972-1987