Value is too difficult to be accurate without seeing the gun. Condition which includes the amount of original finish and original configuration will determine value. Auto 5's with recoil pads (other than Mag 12's) poly-chokes and compensators will reduce value. Expect $250-$800 range for this gun. Recommend taking it to a gun shop for appraisal.
Without anymore information; 100-10000 USD
0-500 USD or so
$350-$650
1962.A Browning light 12 shotgun with the prefix of 3G indicates that your shotgun was made in the year 1963.
Frame
65-550 usd
1943 browning light 12 belguim made $5K
50-450 usd
50-500 usd
It depends on the browning model of shotgun you are asking about,and the condition it is in.
Your Browning light twelve shotgun,not rifle is valued at between 300-550 dollars for a shotgun with between 60%-90% of its original finish remaining,and a good bore.
50-500 usd