12 gauge Belgian Browning shotgun, serial #296305
your browning auto-5 shotgun was made in 1947.
Your browning auto-5 shotgun was produced in 1931.
your browning 16ga auto-5 shotgun was made in 1949.
To many variations over the past 100 yrs to answer.
Your browning auto-5 12ga lightweight shotgun was made by FN for browning in 1967.
If you have a Browning auto-5 shotgun in 12 gauge then it was made in 1927.If you have one in 16 gauge then it was made in the year 1931.
Browning's web site has a sn search function.
Your question is about the Browning auto-5 shotgun.The age of your Browning cannot be determined without you providing a serial number for your Browning.