Since you did not provide the serial number, there is no way anyone can answer your question. The Blue Book of Gun Values has sn data that can assist you. You could also call Browning with the serial number and they will tell you.
your browning auto-5 was made in 1925.
made in 1958
your browning auto-5 was made in 1951.
1928
It was made in 1929
Your Browning auto-5 magnum shotgun was made in the year 1960.
1951 was the year this gun was made
It was made in 1957
This gun was made in 1961
You will have to check the link.
You must call Browning.
1950