You must call Browning with the serial number to find out.
2006
The MW in your serial number indicates that the browning shotgun in question was made in the year 2004.
1928
No way of knowing without you providing the model number/name of the shotgun and the serial number that goes with it.
The 4G prefix to your serial number indicates that your Browning auto-5 light weight shotgun was made in Belgium for Browning in the year 1964.
No serial number = no way to answer.
2006
1977
Go to Browning's site, Support, Date Your Shotgun.
The MW in your serial number indicates that the browning shotgun in question was made in the year 2004.
1951
1928
It was made in 1981.
Impossible to answer without knowing which model.
With the serial number that you provided,if you have a Browning model auto-5 shotgun?Then this shotgun was made by FN of belguim for Browning in 1939.
You will have to call Browning.
Your browning shotgun was made in 1990.