This number should have a "T" and a number associated with it to determine age. Otherwise it would be a FN model and not imported to Browning.
Your browning was made by FN for browning in 1950.
The 71D prefix dates your Browning to the year 1971.
your browning was made in 1976.
You will have to call Browning
The letters NX indicate that your Browning was made in the year 1993.
You will need to call Browning
Your browning was made in 1976.
You will have to call Browning.
You will have to call Browning with the sn.
You will have to call Browning.
You will have to call Browning to find out.
if you are asking about a browning auto-5 shotgun?The year of production of your browning shotgun is 1928.