"Only six digit" isn't that old, as most of the ones out there were produced with 6 digit numbers, and they got up to the low 7 digits. Here's more info:
http://proofhouse.com/browning/a5.htm
So the oldest year the gun could've been made in is 1930.
With the serial number that you have provided,your Browning sweet-sixteen auto-5 shotgun was made in the year 1952.
If your Browning auto-5 shotgun is in 12 gauge,then it was made in the first year of production which was 1903.If you have a 16 gauge auto-5 shotgun,then it was made in the first year of production which was 1909.
You will have to call Browning with the serial number to find out.
your browning auto-5 shotgun was made in 1926 by FN of belguim for browning,with the serial number you provided.
your browning auto-5 was made in 1927.
Your browning auto-5 wa made by FN of belguim for browning in 1931.
You will have to call Browning with the serial number.
With the serial number that you provided,your browning auto-5 shotgun was made by FN of belguim for browning in 1907.
Your browning auto-5 magnum shotgun was made by FN of belguim for browning in 1965.
your browning model auto-5 shotgun was made in 1924.
Your browning auto-5 shotgun was made by FN of belguim for browning in 1957.
You will have to call Browning with the serial number to find out.