You will need to call Browning
The Browning BDA was introduced in the year 1978.If your serial number is 425,then it was made during the first year of production.
1988
Impossible to answer without a serial number.
With the two letters MY in the middle of your serial number,it was made in the year 2002.
1977
1988
de que ano es la browning bda 380 425 nm15253 76.962
They refer to this handgun as the browning model BDA (browning double action auto) pistol.
This is a new gun made in 2009
i would value your browning BDA at between 395-450 dollars in the condition you describe,If your browning is finished in nickel plate I would add 50 dollars to the above stated price.
If you are inclined to go to Brownings home page,you should be able to date your Browning BDA by looking at the customer service site and there will be a title age your browning firearm.
50-800 usd